UNIT#01 INTRODUCTION TO FUNDAMENTAL CONCEPTS OF CHEMSITRY Flashcards
How many unstable radioactive isotopes have been produced through artificial disintegration:
300
The total types of fundamental nuclear sub-atomic particles are there in an atom:
2
Isotopes are:
Chemically Similar
Molecular ions are formed by passing:
➡High energy electron beam
➡α-Particle
A number of moles present in 0.6 g of silica are:
0.01 mole
Volume occupied by 4.4 g of CO2 at STP is:
2.24 dm³
Which one is the molar volume of gas at STP?
22.4 dm³
Number of H+ ions when 0.1 mole of sulphuric acid is completely ionized in water;
2 x 6.022 x 10²²
How many electrons have to be removed to ionize 1.0 x 10-⁶ moles of Ne atoms to Ne+ ions in a neon advertising tube
1.0 x 10-⁶ x 6.022 x 10²³
(No. of electron= n x NA)
When 0.5 moles of Al2(SO4)3 are dissolved in water, a total number of particles produced:
1.5 x 10²⁴
Which of the following contains 1 mole of particles?
Electrons in 1 g of hydrogen gas
The number of moles of CO2 which contain 16 g of oxygen
0.50
The mass of one molecule of O2 is;
32 / 6.022 x 10²³ g
Amount of oxygen in grams which contains 1.5 x 10²² molecules:
40g
(no. of particles = no. of moles x NA)
A number of electrons in half a mole of Na+:
5 NA
3 x 10-²¹ moles of an amino acid having a molecular mass of 200 g mol-1, would have molecules:
1800 molecules
The relative atomic mass of oxygen is 16 amu. What is the mass of 2 moles of oxygen gas?
64 g
Which of the following has maximum mass?
25 g mole of water
The mass of one mole of chlorine gas is:
71 g
Which of the following is not true for one mole?
➡It is counting units ❌
➡It is the gram atomic or gram formula mass of a substance❌
➡It contains 6.02 x 10^23 particles❌
➡It contains a different number of particles for different substances✅
During combustion analysis, which one is used for absorbing carbon dioxide
50% KOH solution
Absorption of CO2 in KOH solution during combustion analysis is:
Chemical change
Which of the following compounds has the highest percentage of oxygen by weight:
H2O
(Depends on molecular mass)
Which of the following compound have an empirical formula, but no molecular formula:
NaCl
(Ionic Compounds do not have molecular formulas)
The sole products of combustion analysis are;
➡CO2
➡H2O
An acid with molecular mass 104 contains 34.6%C, 3.85%H and the rest are O. The molecular formula for acid is:
C3H4O4
6Na + Fe2O3 ➡ 3Na2O + 2Fe
For the above reaction, if you are provided with 230g Na ad 320g Fe2O3, then the limiting reactant is;
Na
Mg reacts with HCl as per the following reaction:
Mg + 2HCl ➡MgCl2 + H2
Given that; Mg=21g and HCl= 21g, then the excess reactant is:
Mg
What volume of oxygen is required for complete combustion of 5cm³ of C2H2
12.5 cm³
11.201 dm³ of methane at STP has _____ moles of hydrogen atoms
0.5
How much Al is required to form alumina with 12g of oxygen
13.5 g
The actual yield is always less than the theoretical yield due to;
➡Side Reaction
➡Reversible Nature
➡Mechanical Loss
Indicate the incorrect statement from the following:
➡A limiting reactant is consumed at the end of the reaction❌
➡Actual Yield is always greater than the theoretical yield✅
➡Stoichiometric calculation can be only done if no side reaction happens❌
➡The empirical formula and molecular formula of some the compounds are same❌
The calculation of the efficiency of a chemical reaction can be checked by knowing the amount of:
The product formed
When one mole of each of the following is completely burnt in oxygen, which will give the largest mass of CO2:
Ethane
If we know the mass of one substance, we can calculate the volume of another substance and vice versa with the help of a chemical equation called;
Mass-Volume Relationship
With the help of spectral data given calculate the mass of Neon and encircle the best option:
20.18 amu
(Relative atomic Mass = (atomic number x percentage) + (atomic number x percentage) / 100
How many chlorine atoms are in 2 moles of Cl:
2 x 6.022 x 10^23 atoms
1 amu is equal to;
1.661 x 10-²⁷ kg
how much volume of O2 is required or formation of SO3 from 0.222 moles of SO2:
2.24 L
The number of single covalent bonds in water molecules are:
2
Ascorbic acid has a high percentage of:
Oxygen
NH3 can be called:
Molecule of compound
The diameter of an atom is;
0.2 nm
No side reaction takes place in:
Stoichiometry
NH3Cl and Ca(OH)2 react to form ammonia. What is the mass of ammonia produced when 100 grams of each is given:
31.7 g
The mass present in 2 dm³ of O2 at STP:
2.8
The product of combustion of H2 is;
H2O
A mole of N in 2g of N2;
1/14
Chemical equations do not tell about the ___ because of certain limitations.
➡Rate of reaction
➡Conditions
➡Pressure
An ordinary microscope can measure the size of an object up to or above;
500 nm
18 g of water contains ____ atoms of hydrogen:
2 x 6.02 x 10²³
The relative atomic mass of copper is;
63.55 amu
25 cm³ of the sample of H2 gas effuses four times as rapidly as 25 cm³ of an unknown gas what will be the molar mass of unknown gas:
32 g/mol
The negative ions having a group of atoms is/are:
➡OH-
➡CO3-²
➡Cr2O7-²
The study of the composition of pure substances in the 17th century clearly shows that few elements are components of many substances:
Quantitative
The concept of ____ gases helps to relate solids and liquids in a quantitative manner.
Molar Volume
The empirical formula of ascorbic acid is:
C3H4O3
NH3 gas can be prepared by heating together solid NH4Cl and Ca(OH)2, if a mixture containing 100g of each solid is heated, then calculate the mass of ammonia:
31.7 g
In combustion analysis, CO2 is absorbed by:
50% KOH
If we know the mass of one substance, we can calculate the volume of another substance and vice versa with the help of a chemical equation called:
Mass-Volume Relationship
One mole of any gas at STP occupies a volume of;
22.414 dm³
How many chlorine atoms are in 2 moles of Cl;
2 x 6.022 x 10²³ atoms
An organic compound has the empirical formula C3H3O if the molar mass of the compound is 110.15 molecular formula of this organic compound is:
C6H6O6
When 8 grams (4moles) of H2 react with 2 moles of O2, how many moles of water will form;
Four
Hydrogen burns in chlorine to produce hydrogen chloride. The ratio of masses of reactants in chemical reaction H2 + Cl2 ➡2HCl is:
1:35.5
A polymer of the simplest formula CH2 has molar mass of 28000 g/mol. Its molecular formula would be;
2000 times than its empirical formula
(n=Molecular Formula Mass/Empirical Formula Mass)
The number of molecules in 9g of ice is;
3.01 x 10²³
How many moles of sodium are present in 0.1 g of sodium?
4.3 x 10-³
An organic sample consisting o carbon, hydrogen and oxygen was subjected to combustion analysis. 0.5439 g of this compound gave 1.0039 g of carbon dioxide, and 0.6369 g of water vapours. The empirical formula of this compound is:
C2H6O
The number of moles of CO2 containing 8.00 g of oxygen is:
0.25
A researcher has prepared a sample of 1-Bromopropane from 10g of 1-propanol. After purification, he made 12 g of product. Which of the following is the percentage yield?
58%
Which one of the following has the same number of molecules as present in 11g of CO2:
4.5 g of CO2
Choose the correct option regarding the number of particles associated with one mole of a substance:
6.02 x 10²³
Determinate the number of moles of O in 10.6 g of Na2CO3:
0.2 moles
Calculate the gram of H2O formed when 8g of CH4 burns in excess of oxygen:
18 grams
While finding the relative atomic mass, which of the following standard is used to compare the atomic mass of chlorine;
Carbon-12
The formula shows the simplest whole number ratio for the atoms of different elements in a compound:
Empirical Formula
3.0 mole of calcium will contain ____ g of calcium.
106.5g
The average atomic mass of Boron is 10.8. It has two isotopes of masses 10 and 11 respectively. What is the percentage of isotopes with an average mass of 10?
20%
The best standard for the calculation o relative atomic mass:
Carbon-12
A piece of diamond embedded in a gold ring weighs 6.0 g. How many moles of Carbon does it contain;
0.5 mole
Iron is manufactured industrially in blast furnaces using Hematite (an iron of ore) and a reducing agent Carbon Monoxide.
Fe2O3 + 3CO ➡2Fe + 3CO2.
Calculate the mass of iron ore used to manufacture 56 g of iron with excess carbon monoxide. Assume that the process gives 100% yield.
80 g
How many moles of calcium carbonate is present in 1.75 kg of calcium carbonate?
17.5 mole
According to the law of definite proportion, what is the mass ratio of hydrogen and oxygen in water?
➡Hydrogen is 11.11%
➡oxygen is 88.89%
How many oxygen atoms are present in 278g of Hydrated Ferrous sulphate?
6.525 x 10²⁴
The water formed in the combustion analysis is usually absorbed by
Mg(ClO4)2
Which contains the highest percentage of Nitrogen?
N2O
(%age of Element = Mass of Element/ Molar Mass of compound x 100 )
A mixture of 10cm³ of oxygen and 50 cm³ of hydrogen is sparked continuously. What is the maximum theoretical decrease in volume?
30 cm³
The number of moles of water in 1 kg of ice is;
55.5 moles
During stoichiometric calculations. which of the following laws must be followed?
Law of conservation of mass
The efficiency of a chemical reaction can be expressed as:
% yield
In a vessel, 10g of N2, 10g H2 and 10g O2 are present. Which one will have the least number?
O2
The empirical formula of glucose is:
CH2O
Which of the followign sets contains only compounds?
➡Carbon Monoxide
➡Phosphine
➡Phosgene
Which of the following has highest atomicity?
Sulphur
S8
Which one of the following pair is isoelectronic:
➡H2O
➡Ne
Which of the following statements is true about isotopes.
They have same number of electrons
Which of the following set of elements form nearly 50% of earth crust.
➡O
➡Mg
➡Si
➡Ca
➡Fe
At present total number of non-radioactive isotopes occur in nature:
240
Atomic mass unit (a.m.u) is equal to;
Mass of one proton
20 amu of neon is:
Relative isotopic mass
Which pair of elements have same number of isotopes?
➡B
➡Cl
Which one of the following has maximum number of isotopes?
Cd
1 mole of different gases have different :
Molar Masses
A pair that have same number of particles:
➡32 g O2
➡32 g N2H4
Equal volumes of N2O and CO2 are taken in ideal conditions, the correct relation between the masses of two gases is:
N2O = CO2
How many moles of neutron are present in one mole of heavy water?
10
15 gram of a gas occupies 11.2 dm³ at S.T.P, the gas is;
NO
(Volume/Molar Volume = Mass/Molar Mass)
Maximum number of molecules will be in:
44 g of CO2
A pair that have same number of moelcules: :
➡32g O2
➡32g N2H4
Equal volumes of N2O and CO are taken in identical conditions, the correct relation between the masses of two gases is:
N2O = CO2
The volume of oxygen gas is 1.12 dm3 at STP, the mass of oxygen is approximately:
1.6 g
The molar volume of a gas depends upon its:
Pressure
Which of the following term is not used for ionic compounds?
Molecular Formula
Which one of the following statements is not involved in the determination of empirical formula
Isotopes of each element
For which of the following compounds, the term empirical formula cannot be applied:
➡NaCl
➡H2O
➡CCl4
The value of “n” in determining molecular formula is obtained from the relation:
n = molecular ,mass/ empirical formula mass
An unknown compound has empirical formula CH3O. Its molar mass is 62g/mole. The compound may be;
CH2(OH)CH2(OH)
(n=62/31=2
Molecular Formula = 2 x CH3O)
While determine molecular formula, the simple multiple “n” is not unity for:
H2O2
An acid with molecular mass 104 contains 34.6%C, 3.85%H and rest is O. The molecular formula of acid is;
C3H4O4
A compound contains 50% S and 50% O by mass. The empirical formula of compound is;
SO2
A pair of compounds that has same empirical formula:
➡Acetic acid
➡Glucose
The simplest formula of a compound containing 50% of element X (Atomic Weight= 10) and element Y (Atomic Weight=20)
X2Y
The number of OH- ions required to react completely with H+ ions produced by 100% dissociation of 49g H3PO4
9.03 x 10²³
Which one act as a limiting reactant when 6 g of carbon and 16g of oxygen react to produce CO2
None of these
21g of CaO is obtained by roasting 50g CaCO3. What is the percentage yield of CaO?
75%
For stoichiometry calculations, we have to assume
All the reactants are completely converted into products
If a sample of ammonium phosphate, (NH4)3PO4 contains 6 moles of hydrogen atoms. Then number of moles of oxygen atoms in the sample is:
2
The law of conservation of mass and the law of definite proportions are obeyed while doing calculation of;
➡Limiting Reactant
➡Theoretical Yield
➡Stoichiometry
How many moles of potassium chlorate should be decomposed completely to obtain 67.2 dm³ of oxygen at STP?
2
“X” gram of carbonate was completely burnt in air as. The weight of solid residue formed is 14g. What is value of “X” in grams.
25
The relation which works best in stoichiometry
Mole-Mole
A ring studded with diamond which weighs 3g. The number of carbon atoms in the diamond are:
1.5 x 10²³
Hydrogen and oxygen have same at STP?
Gram Molecular Volume
Total ion in 5 formula units of NaClO3 is equal to the number of:
10 electrons in Neon
The total number of atoms in 10g of calcium carbonate
3.01 x 10²³
The number of atoms in 16g Ozone is approximately:
6 x 10²³
Which of the following sample conatins the largest number of atoms?
1g of B
The number of moles of CO2 which contains 16g of oxygen
0.50
Stoichiometric caclulation assume that;
➡All the reactants are completely converted into product
➡No side reaction occurs
➡In calculation, law of conservation of mass and law of definite proportions are obeyed
0.36 moles of aluminum and oxygen each react to produce alumina then which of the following is limiting reactant and non-limiting reactant respectively:
Al ➡ Limiting Reactant
O2 ➡ Non-Limiting Reactant
A sample of CaCO3 has Ca=40%, C=12% and O= 48%. If the law o constant proportions s true, then the mass of Ca in 5g of CaCO3 will be:
2.00g
The atom of which element can exist independently
Helium
Hemoglobin moelcule is ___ times than heavier H2:
34,000
(Hemoglobin moelcule is 68,000 times than heavier hydrogen atom)
The atomicity of haemoglobin is;
10,000
An atom of carbon is twelve times heavier than ____ atom.
He
An electron is:
A subatomic particle
Total ions in 5 formula units of NaClO3 is equal to the number of:
10 electrons in Neon
CN-1 is iso-electronic with;
CO
Which of the following term is used or the mass of chlorine 35.5 amu
Realtive atomic mass
Which pair of elements have same number of isotopes
➡Palladium
➡Calcium
Which one of the following has the maximum number of isotopes?
Tin
10 isotopes
Out of 280 isotopes that occurs in nature, ____ have even mass number and even atomic number.
154
A pair of compunds that has same empriical formula:
➡Acetic acid
➡Glucose
Which is correct statement:
Quantitative analysis involves four steps
A compound used as artificial sweetener has formula:
C14H18N2O5
An acid with molecular mass 104 contain 34.6%C, 3.85%H and rest is O, the moelcular formula of acid is:
C3H4O4
There are different steps in determining the empirical formula
Step I. Calculating the number of gram atom
Step II. Determining the atomic ratio
Step III. Determining the percentage composition
What is the correct sequence of the above steps:
III, I, II
The simplest formula of a compound containing 50% of element X (At.wt=10) and 50% of element (At.wt = 20) is;
X2Y
A compound with empirical formula CHO2 and molecular mass 90g/ mole. The molecular formula of the compound is;
(COOH)2
CH2O is the empirical formula of:
CH3COOH
An unknown compound has empirical formula CH3O. Its molar mass is 62g/mol. The compound may be:
CH2(OH)CH2(OH)
3.0 g of NO gas occupies volume;
2.2414 dm³
Which one of the following contains least number of molecules?
16.0 g SO2
One mole of H2SO4 contains:
2.4088 x 10²⁴ atoms of oxygen
Which one has maximum number of atoms:
1g Mg
1 mole of CH3OH and C2H5OH have equal number:
O-Atoms
Which of the following has same number of moles?
➡15g of C
➡30g of Mg
The number of hydrogen atoms in 36g of NH4+¹ is approximately:
8 NA
0.5 mole of H2O is formed when 1 mole H2 reacts with ____ g of O2:
8
Which one is incorrect relation at STP?
➡6g of carbon = 3.01 x 10^23 atoms❌
➡11.2 dm^3 of CO2 = 3.01 x 10^23 molecules❌
➡49g of H2SO4 = 4 moles of atoms✅
➡1 mole of sucrose = 45 moles of atoms❌
The total number of O-atoms in 18g of glucose are:
3.6 x 10²³
Which of the following terms is used for 238 g of uranium:
1g atom
When 0.5 mole of phosphoric acid is dissolved in aqueous solution how many moles of -ve and +ve ions are collected altogether :
2.0
Avogadro’s Number is the number of molecules present in;
Gram Molecular Mass
How many chlorine atoms are in 4 moles of Cl2:
8 x 6.022 x 10²³ atoms
What is the volume (in dm³) of CO2 liberated at STP, when 53 gram of sodium carbonate (molecular mass=106) is treated with excess dilute HCl in following reaction
11.2
One mole each of NO2 and CO2 has same number of:
Molecules
Avogadro’s number of particles of hydrogen gas weighs:
2.016 g
Volume occupied by 7g of N2 present in a mixture:
5.6 dm3
1.4 g atom of nitrogen at STP represents:
2.24 dm³ of N2
The weight of 11.2 dm³ of CO2 at STP would be:
22 g
3 x 10-²¹ moles of an amino acid having molecular mass 200g/mole would have molecules:
1800
2.24 dm³ of CO2 gas at S.T.P has mass:
4.4 g
Block of metals Mg, Al, Fe, Zn of each mass 100g. The maximum number of atoms present in a block of metal.
Mg
(As Mg has the smallest atomic mass)
180 g of glucose contain number of hydrogen atom
7.2 x 10²⁴
The study of quantitative relationship between reactants and products in a balanced chemical equation is known as:
Stoichiometry
Which type of relationship can be studied with the help of a balanced chemical equation:
➡Mass-Mass relationship
➡Mole-Mass relationship
➡Mass-Volume relationship
For stoichiometry calculations, we have to assume:
All the reactants are converted into products
0.5 mole of H2O is formed when 1 g H2 reacts ___ g of O2.
8
Balance chemical equation tells us about:
Direction of reaction
What mass of calcium carbonate in grams is required to produce 5.6 dm³ of CO2.
25 g
Mass of an atom of C is;
➡12/NA
➡12 amu
➡12 x 1.661 x 10-²⁴ g
1 gram molecule refers to amount in grams.
Equivalent to 1 mole of a molecule
1 gram formula refers to;
Amount in grams equivalent to 1 mole of an ionic compound
One mole of SO2 contains:
6022 x 10²³ atoms of sulfur
The mass of 1 mole of magneisum atoms is 24g. What is the mass of one magnesium atom in grams?
3.99 x 10²³
The approximate number of molecules present in 3g of H2O is:
1 x 10^23
The largest number of molecules are present in:
3.6g of H2O
40g of calcium is:
1 gram atom of Ca
How many atoms of carbon are present in 34.2 g of sucrose
7.2 x 10^23
If a ring is made up of 6g of diamond, the number of atoms present in it are:
3.01 x 10^23
Moles of protons in 20g of SO3:
10
The mass of 10^-3 moels of MgSO4 is:
0.12 g
Which of the following contains the same number of atoms as 12g of Mg
10g of Neon
Equal volumes o CO and N2 are taken in identical conditions, the correct relationship between masses o two gases is:
CO=N2
The most significant number of molecules are present in:
36g of H2O
The Avogadro’s number of atom or molecules or formula are units of a substance is called its:
Mole
Which of the following quantity is not 1 mole;
➡1 g of an element❌
➡1 g formula of an ionic compound❌
➡1 atomic mass unit✅
➡1 g molecule of a covalent compound❌
18.02 g of H2O:
6.022 x 10^23 molecules of H2O
A unit which represents 6.02 x 10^23 particles is called:
➡Mole
➡1 gram molecule of nitrogen
➡1 gram ionic mass
% of nitrogen in urea (NH2CONH2):
46.6%
A compound contains 50% sulphur and 50% of oxygen by mass. The empirical formula of the compound is:
SO2
The empirical formula of vitamin C (Ascorbic Acid) is:
C3H4O3
If the empirical formula of a compound is CH2 and its molecular mass is 56 amu. What will be its molecular formula?
C4H8
Molecules formula = n x empirical formula
Which statement is correct about “n”
It can never be zero
Styrene has the empirical formula CH, and there is 92.2 % C and 7.75% hydrogen. if the molar mass is 104g/mol, what will be the integral multiple (n) to get the molecular formula
8
Combustion analysis is performed for the determination of:
The empirical formula of the compound
The stoichiometric calculations for a chemical reaction results in:
Theoretical yield
5603 cm^3 of hydrogen gas at STP contains atoms of hydrogen.
3.01 x 10^23
Gram atoms of hydrogen in 5.5 g H2
5.50
4g of an unknown gas occupies 5.6 dm^3 volume, at S.T.P the gas is;
CH4
10 moles of HCl are added to excess magnesium and form 4 moles of hydrogen gas percentage yield is:
80%
Which of the following is a limitation of a balanced chemical equation:
➡Conditions and Rate of Reactions
➡Physical state and Mechanism
How much oxygen is required to react 16g of S to form SO2
16g
If the actual yield of a product is 8g, then the theoretical yield will be ____ while the reaction is 80% efficient.
10g
4 moles of hydrogen react with 5 moles of oxygen to form water, and identify the excess reagent:
Hydrogen
If 15g of sulphur is burnt, what volume of SO2 is produced at STP?
10.51 dm^3
If you have 3.5 moles of hydrogen and 5 moles of nitrogen to produce ammonia. How much ammonia is produced
39.6 g
Which of the following conditions of temperature and pressure are the standard conditions?
➡0°C and 1 atm pressure
➡273K and 14.7 PSI
➡32°F and 760 torr
Which one is the experimental equation:
➡Rate equation
➡Rate expression
2.8 g of N2 molecules contain number o chemical bonds:
1.8 x 10^23
A limiting reactant is one which;
Gives minimum amount of product under consideration
An acid with molecular mass 104 contains 34.6%C, 3.85% H and the rest are O. The molecular formula of acid is;
C3H4O4
The total number of atoms in 9g of water are;
9.03 x 10^23
One-gram molecules of different gases have all the following properties same at STP except:
Masses
A pair that have the same number of molecules;
➡32 g O2
➡32 g N2H4
One mole of which of the following will have a different number of electrons than others
CO+1
The total number of O-atoms in 18g of glucose are:
3.6 x 10^23
21 g of CaO is obtained by roasting 50g of CaCO3. What is the percentage yield of CaO?
75%
The absorption of CO2 in 50% KOH leads to:
Chemical Change
A sample of 100cm^3 of dilute H2SO4 contains 0.1 moles of acid. What is the hydrogen ion concentration in the solution per dm^3?
2 moles
The number of moles of KMnO4 that contain 1 mole of the oxygen atom
0.25 moles
A pair of compounds that has the same empirical formula
➡Acetic acid
➡Glucose
Elemental analysis is performed to determine:
The empirical formula of a compound
Hydrogen and oxygen have the same at STP
Gram molecular volume
Equal volumes of N2O and CO2 are taken in identical conditions, the correct relation between the masses of two gases is:
N2O = CO2
Which one has the maximum number of atoms
1g Mg
Which one will produce the largest number of negatively charged ions in case of 100% dissociation of 1 mole.
FeCl3
1 mole of CH3OH and C2H5OH have an equal number
O-atoms
Mass spectrometry is used to determine the:
➡Number of isotopes of an element
➡Relative abundance of isotopes
➡Relative isotopic masses
The stoichiometric calculations or a chemical reaction results in:
Theoretical Yield
1 gram molecule refers to the amount in grams
Equivalent to 1 mole of a molecule
A number of H+ ions when 0.1 moles of sulfuric acid is completely ionized in water:
2 x 6.022 x 10^22
1 gram formula refers to:
Amount in grams equivalent to 1 mole of an ionic compound
How many electrons have to be removed to ionize 1.0 x 10^-6 moles o Ne atoms to Ne+ ions in a neon advertising tube
1.0 x 10^-6 x 6.02 x 10^23
One mole of SO2 contains:
6.022 x 10^23 atmos of sulfur
56.4 cm^3 of H gas at STP contains atoms of hydrogen:
3.01 x 10^23
The number of moles present in 0.6 grams of silica is:
0.01 mole
Gram atoms of hydrogen in 5.5g H2
3.01 x 10^23
% of nitrogen in urea(NH2CONH2)
46.6%
One mole of potassium chlorate is thermally decomposed and an excess aluminium is burnt in a gaseous mixture. how many moles of aluminium oxide are formed?
2KCLO3 ➡KCl + 3O2
4Al + 3O2➡2Al2O3
1.0
In a mass spectrometer, increasing the electric field with constant magnetic field results in:
decreased radius “r”
When 0.5 models of Al2(SO4)3 are dissolved in water, the total number of particles produced
1.5 x 10^24
The mass of one mole of magnesium atoms is 24g. What is the mass of one magnesium atom in grams?
3.99 x 10^-23
Which of the following contains 1 mole of the stated particles
Electrons in 1g of hydrogen gas
During combustion analysis, which one is used for absorbing carbon dioxide:
50% KOH solution
Which one is the mono-isotopic element:
Fluorine
Molecular ions are produced in mass spectrometers. Which type of molecular ions formed more abundantly
Positively charged
The height of the peak in the mass spectrum shows:
Relative abundance
The separation of different isotopes in the mass spectrometer is done on the basis of:
different m/e
A compound contains 50% sulfur and 50% oxygen by mass. the empirical formula of the compound is;
SO2
Equal volumes of CO and N2 are taken in identical conditions. The correct relationship between the masses o two gasses is:
CO=N2
The approximate number of molecules present in 3g of H2O is:
1 x 10^23
The mass of one molecule of O2 is:
32/6.02 x 10^23
Combustion analysis is performed for the determination of:
The empirical formula of the compound
1 amu is equal to:
1.66 x 10^-21 mg
A haemoglobin molecule is how many times heavier than a helium atom
17000
Which of the following is a pure substance
Distilled Water
How many isotopes are preset in palladium
Four
Naturally occurring isotopes of silver are
Two
Atoms having the same mass number but different atomic numbers are called:
Isobars
40g of calcium is:
1 gram atom of Ca
Amount of oxygen in grams which contains 1.5 x 10^22 molecules
0.80
What volume of oxygen is required for complete combustion of 5cm^3 C2H2
12.5 cm^3
How many atoms of carbon are present in 34.2g
1.2 x 10^22
Absorption of CO2 in KOH solution during combustion analysis is:
Chemical cHange
10 moles of HCl are added to excess magnesium and form 4 moles of hydrogen gas percentage yield is;
80%
If you have 3.5 moles of hydrogen and 5 moels of nitrogen to produce ammonia. How much ammonia is produced
39.6 g
How many unstable radioactive isotopes have been produced through artificial disintegration
300
The empirical formula for vitamin C is:
C3H4O3
Number of electrons in half a mole of Na+
5.5 NA
The amount of products obtained from the balanced chemical equation represents
Theoretical yield
Which of the following compounds has the highest percentage of oxygen by weight:
CH3OH
The volume occupied by 4.4 g of CO2 at STP is:
1122 cm^3
If a ring is made up of 6g diamond, then a number of atoms present in it are:
1.5 x 10^23
Which of the following has the least mass
1 mole of Neon gas
If the empirical formula of a compound is CH2 and its molecular mass is 56 amu. What will be its molecular formula?
C4H8
Which of the following compound have an empirical formula, but no molecular formula?
NaCl
Moles of protons in 20g of SO3
10
Which of the following is a limitation of a balanced chemical equation
➡Conditions and Rate of Reaction
➡Physcial State and Mechanism
3 x 10^-21 moles of an amino acid having a molecular mass of 200 g mol-1, would have molecules
1800
Molecules formula = n x (empirical formula), which statement is correct about ‘n’
it can never be zero
11.207 dm^3 of methane at STP has _____ moels o hydrogen atoms.
2
The element showing 100% abundance in the mass spectrum is;
Arsenic
Which of the following isotopes will have maximum deflection in magnetic field during mass spectrometric analysis:
C-12
Which of the following contains the same number of atoms as 12g of Mg?
10 g Neon
Which is a molecular ion
NH3+
The sole products of combustion analysis are:
➡CO2
➡H2O
Styrene has the empirical formula CH, and there are 92.2% and 7.75% hydrogen. If the molar mass is 104 g /mole, what will be the integral multiple(n) to get the molecular formula
8
An acid with molecular mass 104 contains 34.6%C, 3.85%H and the rest are O. The molecular formula of acid is:
C3H4O4
How much oxygen is required to react 16g of S to form SO2
16 g
How much Al is required to form alumina with 12g of oxygen?
13.5 g
An element X has two isotopes X-35 and X-37 with an average atomic mass of 35.5 amu. Relative abundance of bot isotopes is repsectively
➡75%
➡25%
An element has two isotopes A-63 and A-64 with an average atomic mass of 63.5 amu. The relative abundance of lighter isotopes is;
50%
At STP a gas which has maximum value;
4 g of H2
The negative ion having group of atom is/are:
➡OH-
➡CO3-2
➡Cr2O7-2
The term relative atomic mass is used for:
35.5 amu Cl
All elements of the periodic table chemically differ from each other due to:
Atomic Number
The correct relation between empirical formula and molecular formula is:
Empirical Formula = Molecular Fromula/n
Empirical formula is the simplest atomic ratio of atoms in a molecule. Which compound does not have empirical formula CH2O
Methanol
Combustion analysis is primarily used to determine:
Empirical Fromula
Mole of a substance can be related:
➡Avogadro’s number
➡Molar Mass
➡Molar Volume
The mass of one mole of electron is:
0.55 mg
The number of carbon atoms in 45g of C6H12O6:
1.50 x NA
Combustion analysis cannot determine empirical formula of:
Amino acid
Volume of nitric oxide gas produced by the following reaction of 14g N2 with excess oxygen is:
22.4 dm^3
Which of the following has maximum mass:
0.5 mole of Ca
3NA number of ionizable H+ are present in 1 mole of:
H3PO4
Empirical formula of a compound CH2O with molar mass 60 g/mol belongs to which class of biochemical compound:
Carboxylic acids
What is the mass of CaCO3 which on heating produces 0.5 moles of CO2 gas:
50g
Select the suitable term about 17g of OH-:
1g ion
How many gram atoms in 0.1 kg of calcium:
2.5
Which statement is incorrect about Helium:
He exist as diatomic molecule only
A sample of liquid consisting of carbon, hydrogen, and oxygen was subjected to combustion analysis, 24g of compound gave 22g of CO2. What is % age of carbon
25%
1 gram atom of carbon is present in one mole of which of the following specie/substance.
CaCo3
When 2g H gas and 16g O2 gas react completely to produce H2O.What is non-limiting reactant.
Both are consumed completely
A man drinks 250cm3 water in a glass containing 18g glucose the minimum number of atoms received by him are of:
Carbon
Determine the number o moles of H-atoms in 18g of C6H12O6:
0.6 mole
Which is a macromolecule:
Haemoglobin
The moelcular mass of D2O is:
(D2O is heavy water)
20.03
Total number o oxygen atoms are present in 44g of N2O:
1 NA
One mole of an organic compound is completely burnt in excess of oxygen which compound exactly five moles of water:
Butanol
The molar mass of compound is 180g/mol with 40%, 6.67%, 53.3% of C, H and oxygen respectively calculated from combustion analysis. Empirical formula of this compound is:
CH2O
Number of grams of NaOH required for complete neutralization of 1 mole of H2SO4 on its complete ionization:
80g
H2O, HF and Na+ have same:;
Number of electrons
Number o molecules in 1.8g of glucose:
6.02 x 10^21
How many chlorine atoms are in 2 moles of Cl:
2 x 6.02 x 10^23
The statement which is incorrect about stoichiometric calculation:
Reactions may be reversible
The formula which shows the simplest whole number ration for the atoms of different elements in a compound:
Empirical Formula
The amount of product calcualted from the balanced chemical equation represent:
Theoretical Yield
In combustion analysis, H2O abosrber contain:
Mg(ClO4)2
1.5 x 10^23 molecules of O3 at STP has mass;
12g
Mass of Al in 51g of Al2O3:
27g
Mass of one magnesium atom is;
➡3.98 x 10^-23g
➡24g/NA
➡24amu
21g of lime is produced if 50g of lime stone is roasted. What is % yield.
75%
A balanced chemical equation tells us about the;
Quantitative relationship between reactants and products
2.8g of unknown gas occupies a volume of 2.24 dm3 at STP unknown gas is:
CO
Which is correct statement about limiting reactant:
➡It is concept of stoichiometry
➡It is taken in less amount than stoichiometric amount
➡Control amount of product
Relationship between empirical and molecular form is M.F = n(E.F). For which compound value of n=1:
C12H22O11
Mole of SO3 if it contains 16g of oxygen:
1/3
How many moles of of NH3 are produced on reacting 3 moles of N2 with 10 moles of H2:
6 moles
A compound has an empirical formula CH2O and molecular formula mass as 90g/mol, Identify the compound:
C3H6O3
What is volume occupied by 2.2g of N2O at STP:
1120.7 cm^3
5.6 dm3 of oxygen gas is collected at STP from Hydrilla plant by photosynthesis. The mass of oxygen produced is:
8g
The compound which cannot be analyzed by combustion analysis:
Urea
9.8g of sulphuric acid has mass of sulphate ions:
9.6g
9g of ice has number of covalent bonts:
6.02 x 10^23
A well known ideal gas is enclosed in a container having volume 5603cm3 at STP. Its mass comes out to be 16g. The unknwon gas is:
CO2
The efficiency of a chemical reaction can be checked by calculating:
Amount of product ormed
Identify the type of yield that can be obtained thorugh experiment:
Actual Yield
If 24g of organic compound is burnt in combustion tube which gives 22g of CO2. %age of carbon is:
25%
Which of the following term is correct for H=1.008 amu
➡Relative atomic mass
➡Average atomic mass
➡Fractional atomic mass
7g of CaO is produced if 50g of CaCO3 is roasted. Find %age yield.
25%
Under standard conditions, stoichiometry can be applied to:
2H2O➡2H2 + O2
Identify the correct statement about acetic acid and oxalic acid
Both have differnet empirical formula
5g of C and 10g of Mg contain equal number of:
Atoms
Volume occupied by 114g of F2 at STP is:
67 dm3
Which of the following sub-shell does not exist:
3f
An electron in a hydrogen atom makes
a transition from an energy level E1 to one with energy E2 and simulatenously emits a photon. The wavelength of the emitted photon is:
hc/E2 -E1
Identify the element that have same number of s and p electrons:
Mg
Energy emitted or absorbed by a body in the form of quanta. This is:
Planck’s Quantum Theory
Unit of Planck’s constant is:
J/m
The third electron of L atom will have quantum number values;
➡n=2
➡l=0
➡m=0
➡s=+1/2
For a given value of azimuthal quantum number l, the total number of values for magnetic quantum number ‘m’ are given by:
2l -1
The magnetic quantum number for the valence electron of K(Z=19) is:
Zero
Quantum number which describe shape of orbitals:
Magnetic quantum number
Number of electrons in chloride on:
18
With the increase in value of principal quantum number which one will not change:
Shape of p-orbitals
Which one orbital is bilobed with collar:
dz2
A covalent compound of simplest formula CH has molar mass of 78g/mol. Its molecular formula will be:
6 times of its empirical formula
H2 burns in Cl2 to produce HCl. The ratio of masses of reactants in chemcial reaction:
H2 + Cl2 ➡2HCl
1:35.5
Which of the following has same number of molecules as present in 11g of CO2:
4.5g of H2O
1 mole of CH3OH and 1 mole of C2H5Oh have equal number of:
O-atoms
Which one will produce largest number of negatively charged ions in case of 100% ionization o f1mole of:
AlCl3
A compound has 50% of A (molecular mass=20g/mol) and 50% of B (molecular mass=10g/mol). Empirical formula is:
AB2
1 mole of each N2O and CO2 has same number of:
➡Molecules
➡Atoms
➡Electrons
Atomic mass unit is:
1/12th of mass of one C-atom
The number o atoms present in 0.1 mole of oxygen gas are:
2 x 6.02 x 10^22
The maximum amount of the product that can be prodcued by a given amount of a reactant, according to balanced chemical equation is called:
Theoretical Yield
Which of the following compounds does not show same molecular and empirical ormula:
(CHO)2
The number of oxygen atoms in 44g of CO2 is:
2NA
Number of electrons in 1.8g of steam.
NA
1 gram moelcule of methane has mass of:
16g
Avogadro’s number o atoms are present in:
3.2g CH4
The number of molecules in 11g of N2O is:
1.505 x 10^23
1 amu is equal to:
1.661 x 10^-21 mg
In combustion analysis, H2O vapours absorption is an example of:
Neutralization Reaction
14g of a gas contains 3.01 x 10^23 molecules at STP. The gas is:
N2
Which type of relationship can be studied with the help of balanced chemical equation:
➡Mass-Volume
➡Mole-Mole
➡Mole-Volume
The mass of an atom compared with mass of one atom of C-12 is called:
Relative atomic mass
58.5 amu is ____ of Rock salt.
Relative Formula Mass
All reactants are converted to product and no side reaction takes place are basic assumption while doing calculations for:
➡Limiting Reactant
➡Theoretical Yield
➡Stoichiometry
18g of water is produced if 2g of hydrogen react with ___ of oxygen.
16g
Avogadro’s number represents the number of:
Atoms in 24g of Mg
Which one of the following terms is not used for ionic compounds?
Molecular ormula
98g H2SO4 contains number of moles of ions:
3.0 moles of ions
Cationic molecualr ions are produced by:
➡α-rays
➡Beam of electrons
Isotopes differ in:
Properties which depend upon mass
Which one of the following mathematical relationships is correct for (m/e) in connection with Dempster’s mass spectrometer?
m/e = H2r2/2E
Symbol indicates not only the name of elements but also represents all of the following EXCEPT:
1 amu
Which of the following is not mono-isotopic element?
Cl
Which of the following statements is incorrect?
Number of cationic molecular ions is less than number of anionic molecular ions
What volume of oxygen gas is required for the complete combustion of 5cm3 of ethyne (C2H2)?
12.5 cm#
The relative atomic mass of boron, which consists of isotope of Boron-10 and Boron-11 is 10.8 amu. What is the percentage of Boron-10 atoms in the isotopic mixture.
20%
How many carbon atoms are present in 34.2g of sucrose.
(Molecular Mass of Sucrose=342)
7.2 x 10^23
What is the number of molecules in 1000cm^3 of nitrogen gas under room conditons.
2.5 x 10^22
Which is the correct sequence of stages in mass spectrometer?
Ionization , Separation, Detection, Amplification, Recording
How many total number of atoms are present in 49.0g of sulhpuric acid:
7 x 3 x 10^23
An organic compound has empirical formula CH2O. If molar mass of the compound is 90grams, then molecular formula of this organic compound would be:
C3H6O3
How many bromine atoms are in 3 moels of bromine element?
3 x 6.022 x 10^23 atoms
Carbon dioxide gas produced during combustion analysis of given organic compound is abosrbed in 50% of KOH solution. It is a:
Chemical Change only
In the experimental determination of the percentage of carbon and hydrogen in an organic compound, water absorbed by:
Mg(ClO4)2
12g of magnesium (Mg) reacts with dilute sulphuric acid to produce hydrogen gas. The amount of hydrogen gas produced is:
1g
Identify the correct statement about yield.
Experimental error does not affect actual yield
A solution contains three components A, B and C in the molar ratio 3:6:1. The percentage of mole fraction of component A is:
30%
Isotopes of an element have all of the following different properties EXCEPT:
They have diferent chemical properties
The combustion analysis of an organic compound shows
60% carbon, 8% hydrogen and 32% oxygen. If the
molecular mass of the given organic compound is 200,
then the molecular formula of the organic compound is
(Ar of C = 12 amu, H = 1 amu and O = 16 amu):
C10H16O4
Ascorbic acid (vitamin C) contains 48% carbon, 4% hydrogen and 48% oxygen. Which of the following iempirical formula of ascorbic acid?
C4H4O3
The number of moles of sodium hydroxide present in 2.5dm3 of 0.5M aqueous solution is:
1.25
Calcium reacts with excess oxygen to form calcium oxide (CaO) as shown in the equation:
2Ca + O➡2CaO2
The maximum mass of CaO formed when 4.0g of calcium
is burnt in excess oxygen (Ar values Ca = 40amu, O = 16amu):
5..6 g
If we know the mass of one substance, we can calculate the volume of other substance and vice versa with the help of a balanced chemical equation, which is called:
Mass-Volume Relationship
By using the value of Avogadro’s number. Calcualte the total number of atoms in 7.1g of Cl-element.
1.2 x 10^23 Cl-atoms
Whoch one of the following has same number of moelcules as present in 11g of CO2?
4.5 g of H2O
28g of N2 gas at STP will occupy the volume of:
22.414 dm^3
Which of the following statements about 12g sample of C-12 is incorrect?
The number of C-atoms is the same as electrons in 16 g of S
Isotopes of an element possess:
Same chemical but different physical properties
When lime stone is roasted, quick lime is produced. The actual yield of CaO is 0.5 kg when 1kg of limestone is roasted. What is the percentage yield of this reaction?
CaCO3 ➡CaO + CO2
89.3%
Which of the following statement is correct:
The properties of an element mostly corresponded to the most abundant isotope of that element
A sample in the ionization chamber o mass spectrometer is ionized by:
Electrons
One mole of CO2 contains:
➡22-Moles Electrons
➡6.022 x 10^23
Total number of atoms present in 49.0g H2SO4 are:
7 x 3.011 x 10^23 number of atom
Mass spectrum is obtained by plotting graph between:
m/e along x-axis and relative number of ions along y-axis
The number of moles of CO2 which contains 16g of oxygen is:
0.5
Which one of the following is not generally same for one mole of different gases at STP?
Molecualr Mass
4g H2 reacts with 32.0g O2 to produce water. Which of the following statements is correct?
2.0 mole water is produced
Which of the following is correct sequence of processes involved in modern mass spectrometer?
Vaporization, Ionization, Electric Field, Magnetic field, Ion Collector, Amplification and Recordng
The volume occupied by 1.6g of O2 at STP is:
1.12 dm3
Which of the followng is incorrect isotopes of an element?
They have different position in the modern periodic table
The electrometer is also called as:
Ion Collector
Which information obtained from electrometer gives the relative abundance o ions of a definite m/e value?
Strength of electric current
Thee combustion analysis of an organic compound shows 60% carbon, 8% hydrogen and 32% oxygen. If the molecualr mass of the given organic compound is 200, then the molecular formula o the organic compound is:
C10H16O44
Which represent the simple ratio of atoms present in a compound?
Empirical Formula
Which of the following contains one mole o the stated particles?
Electrons in 1g of hydrogen gas
Total number of atoms present in 17g of hydrogen peroxide is:
1.2 x 10^24
0.5 mole of magnesium is burnt in excess oxygen. How much amount of MgO is produced in this reaction
2Mg + O2 ➡2MgO
20g
Which one of the following is CO2 abosrber?
KOH
Which one of the following is not a water absorber?
➡conc. H2SO4❌
➡Anhydrous CuSO4❌
➡CaCO3✅
➡Mg(ClO4)2❌
Which one of the following compound doesn’t have same molecular formula and empirical formula?
CH3COOH
For those compounds which have same moelcular and empirical formula, the value of simple multiple ‘n’ is?
1
The value of simple mutliple ‘n’ is:
The ratio of moelcular mass and empirical mass
One gram molecular mass of diferent substances expressed in grams must possess:
Some times same masses and some times different masses n them
One mole of different compounds has:
Diferent masses but same number of molecules
Which one of the following statement is not true about molecule?
Molecule always consist of more than one atoms
Molar volumes is 22.414 dm3 , it is true:
Only when the gas is ideal
One mole of an ideal room temperature and pressure occupies a volume of:
22.414 dm3
414 dm3 of each gas at STP has:
a different mass but the ame number of molecules
Many elements have fractional atomic mass. This is because:
Atomic masses are average masses of isotopes proportion to their relative abundance
For a reaction X +2Y➡Z. The amount of Z formed by starting the reaction with 5 moels of X and 8 moels of Y:
4 moles
One mole of water and one mole of methane have an equal:
Number of molecules
A compound has an empirical formula CH2Cl, and molecular/formula mass as 99g/mol, identify the compound
C2H4Cl2
The Avogadro’s number is the number of:
Number o the molecules of CO2 in 44g
The empirical formual of a compound s CH2O. What other information is needed to determine its molecular formula?
Relative molecular mass of the compound
100g of CaCO3 is decomposed, the CO2 produced occupies a volume at STP
22.414 dm3
Methanol burns with oxygen. If 1 mole of methanol is burnt in oxygen, then how many moles of water are prodcued:
2 moles
The number of moles of O2 produced by thermal decomposition o 245g of KClO3.
(Molar mass of KClO3 = 122.5 g/mol)
3 moels
The reactant left un-used after completion o reaction is knwon as:
➡Reactant in excess
➡Non-Limiting Reactant
The quantity of a product that is actually produced in a chemical reaction is called:
Actual Yield
50g limestone is heated to give 14g CaO in a chemical reaction. What will be the % yield of this reaction
50%
8g of gas “X” occupies 11.207 dm3 volume at STP. The gas “X” will be:
CH4
Mass of water in 100 moels o ice is:
1.8 kg
The realtive atomic mass of chlorine is 35.5 amu. What is the mass of 2 mole of chlorine gas:
142g
The Na2CO3 has 106 g. This is called its:
Formula Mass
The volume occupied by 4.4g of CO2 gas at STP is:
2.24 dm3
Complete oxidation o one mole of an organic compound requires three mole of oxygen gas. The formula of the organic compound will be:
CH3CH2Oh
A limiting reactant is the one which:
Gives the minimum amount of product
Which statement is incorrect:
One gram atom of sodium is equal to one gram sodium
Combustion analysis is used to determine the _____ of an organic compound:
Empirical Formula
23g of sodium and 24g of magnesium have equal ____ in them.
Number of atoms
720g of glucose contains how many moles of glucose.
4
An unknown compound has empirical formula CH3O. Its molar mass is 62g/mole. The compound may be:
CH2(OH)CH2(OH)
Quantitative relations between reactants and products in a balanced chemical equation is known as:
Stoichiometry
32g mof methanol contains:
➡1g-atom of “C”
➡4g-atom of “H”
➡1g-atom of “O”
The efficiency of a chemical reaction can be determined with the help of:
%age Yield
What is the mass of 2.5 moles of Al2O3
255g
58.5 amu mass of NaCl called as:
Formula Mass
When 0.5 mole of NaCl is dissolved in water, it produces Na+ ions equal to:
3.01 x 10^23
NH3 is an important raw material in the manufacture of fertilizers. It is obtained by the combination o N2 and H2. How many moles of N2 are required to manufacture 3 moles of NH3.
1.5 moles
How many moles of oxygen moelcuels are there n 89.656dm3 of oxygen gas at STP
4 moles
How many number of moles of hydrogen atoms are present in 36g H2O:
1 mole
The actual yield may be less than the theoretical yield due which of the following reason:
➡Side reactions may produce by-products
➡Some reactions are reversible
➡Mechanical loss takes palce due to filtration and distillation
Which of the following terms is used for 18g H2O?
g- molecule
A piece of diamond embedded in a gold ring weighs 6000mg. How many number of
moles of carbon does it contain?
0.5 mole
ne mole of helium gas can occupy 22.414 dm3 volume at
298K and one atm pressure
Number of water molecules in 9g of ice.
3.01 x 10^23
Number of moles of NO2 which contains 16g oxygen is:
0.50 mole
A balanced chemical equation tells us about:
Quantitative relationship between reactants and products
Which is true about acetic acid and oxalic acid?
Diferent empirical formula
CH2O is tge empirical ormula of:
➡Acetic acid
➡Glucose
➡Lactic acid
Which of the following terms is used for 238g of uranium:
1g atom
Total number o electrons present in 34g of OH- are:
20Na
The number of molecules in one mole atom of a substance.
NA of atoms
For stoichiometry calculations ,we have to assume:
All the reactants are completely converted into products
What wll be volume of 1.5 moels of chlorine molecules occupy at STP.
33.6 m3
2.5 mole of H2 and 2.5 mole of O2 at same temperature and presure have equal:
➡Volume
➡Molecules
➡Atoms
While finding the relative atomic mass, which of the following standard is used to compare the atomic mass of chlorine
Carbon-12
One mole o ethanol and one mole of ethane have equal:
Number o molecules
The amount o product obtained without perfforming an experiment is knwon as:
Theoretical Yield
1 amu is equal to:
1.661 x 10^-27 kg
An organic compound has empirical formula C3H3O if molar mass of the compound
is 110.15 molecular formula of this organic compound is:
C6H6O2
The number of molecules in 44.5 g of ice is:
1.5 x 10^23
The formula which shows the simplest whole number ratio for the atoms of different
elements in compound
Empirical Formula
Number o covalent bonds in 1.7g of NH3:
1.8 x 10^23
11.2 dm3 of an ideal gas at STP weighs 15g predict the gas.
NO
