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