Mole Concept and Stoichiometry Flashcards
basic unit/quantities
mole
of atom/element/compound
mole
avogadroβs number
6.02x10^23
are non-zero digits and any zeroes contained between non-zero digits counted as significant figures
yes
how many significant figures in 300042
6 significant digits
are leading zeroes significant
no
how many significant figures in 0.0000034
2 significant figures
do trailing zeroes count if there is a decimal point
yes
how many significant figures in 0.0002500
4 significant digits
can trailing zeroes count if there is no decimal point
no
how many significant figures in 19000000
2
formula for molar mass
mass(g)/moles (mol)
illustrate the mole map
grade yourself accordingly
Determine the mass (g) of 2.50 moles of Na
57.5g (3 s.f.)
How many moles are present in 50.0g in MgCl2?
0.525 moles
How many Fe atoms are present in 10.0 moles of Fe
6.02π₯10^24 ππ‘πππ πΉπ
Calculate the # of molecules present in 25.0g of CH3COOH (acetic acid)
2.51π₯10^23 ππππππ’πππ ππ πΆπ»3πΆπππ»
Determine the # of Al atoms in 25.0 moles Al2S3
3.01π₯10^25 ππ‘πππ π΄π
2 moles of Na is allowed to react with excess Cl2 to produce NaCl. Determine the # of moles of NaCl formed after the reaction
2 πππππ πππΆπ
What mass (g) of Mg is needed to react with excess oxygen gas to produce 2.0 moles of MgO
48.608π ππ ππ
used to refer to extremely small particles such as atoms, molecules, and ions
mole
SI unit to denote the amount of substance
mole
amount of substance that contains as many elementary particles as in 0.12kg of carbon-12.
mole
experimentally determined value to describe a mole of a pure substance
6.02x10^23
honored using the Avogadroβs number
Amadeo Avogadro
1 mole of any substance = ____particles
6.02x10^23
1 mol of Ag atom will contain ___ Ag atoms
6.02x10^23
born on August 9 1776 in Turin Piedmont-Sardinia (now part of Italy)
Lorenzo Romano Amadeo Carlo Avogadro
father of Avogadro (lawyer), well-known magistrate and senator in Piedmnt region of northern Italy
Fillippo Avogadro
Avogadroβs mother, a noblewoman
Anna Vercellone of biella
Avogadro received his doctorate in ecclesiastical law
age of 20
Three different types of molecules that Avogadro described
integral molecule
constituent molecule
elementary molecule
when did Avogadro stated that βequal volumes of all gases at the same temperature and pressure contain the same number of moleculesβ
1811
was given as equivalent to 1/12 the mass of carbon-12 and that all other atomic masses of the elements are determined relative to carbon 12
atomic mass (amu)
as such as the mass in grams of one mole of any substance is called with the unit of grams/mole
molar mass
Determine the molar mass of the following compounds:
A. MgO
40.303 g/mol
Determine the molar mass of the following compounds:
H2SO4
98.5206 g/mol
Determine the molar mass of the following compounds:
Zn3(PO4)2
=386.08 π/πππ
Francium, the alkali metal named after France, was discovered by Marguerite Perey in 1939. Though known to be radioactive, as of today it has no known uses because it is unstable and rare. Determine the number of atoms present in 2.50 moles of Francium, Fr.
1.505525π₯1024 ππ‘πππ ππ πΉπ
Lithium is an element that produces a red flame. Calculate the number of moles in Li in 7.35x1024 atoms of Li
12.20504475 πππππ ππ πΏπ
Incomplete combustion of fuels produce carbon monoxide, a colorless, tasteless, odorless poisonous gas. Calculate the number of CO molecules present in 4.50 moles of CO.
2.709945π₯1024 ππππππ’πππ πΆπ
Convert 5.78x1022 molecules released in the atmosphere in number of moles
0.09597980771 πΆπ ππππππ’πππ
determines the number of moles present for every mole of the compound
subscript
Nitrous oxide with the molecular formula N2O is also known as laughing gas. It is colorless and odorless and is known to have analgesic and anesthetic purposes
Calculate the mass (g) of 8.75 moles N2O
385.09625 π π2π
Nitrous oxide with the molecular formula N2O is also known as laughing gas. It is colorless and odorless and is known to have analgesic and anesthetic purposes
If the mass of N2O is 35.89g, what is the corresponding number of moles?
0.8154 πππππ π2π
Hydrogen cyanide, HCN, also known as prussic acid is a toxic compound that boils above 26oC. It can readily be absorbed through inhalation, ingestion, or even by dermal exposure.
Calculate the number of moles of H atom present in 2.50 moles of HCN
2.50 πππππ π»
Determine the number of N atom present in 1.25g of HCN
2.784685525π₯1022 ππ‘πππ
Compute the mass in grams of H and N atoms present in 5.85 moles of HCN
81.90351 π π
used as a safety device in most vehicles
air bags
occurs that allow the air bag to inflate and provide protection during collision
chemical reactions
its decomposition to sodium metal and nitrogen gas is the main chemical reaction involved
sodium azide
also incorporated in air bags to ensure that the bag is inflated enough
oxidizers
ordinary airbag has what volume
36 liters
hwow many sodium azide must be decomposed to produce the volume of 36 liters of nitrogen gas
130g sodium azide
science of measuring the quantitative proportions or mass ratios in which chemical elements stand to one another
stoichiometry
Stoicheion means
element
metron means
measure
involves the mass relationships between reactants and products in a chemical reaction
stoichiometry
all reaction stoichiometry relationships start here
balanced chemical equation
gives the relative numbers of moles of reactants and products
equation
is used to solve problems from the balanced equations
ratios
N2 + 3H2 -> 2NH3
how many are the following:
Number of atoms: ___ atoms of Nitrogen, _ atoms of Hydrogen, and _ atoms of ammonia
Number of atoms: 2 atoms of Nitrogen, 6 atoms of Hydrogen, and 8 atoms of ammonia
N2 + 3H2 -> 2NH3
how many are the following:
Number of molecules: _ molecule of Nitrogen, _ molecules of hydrogen, and _ molecules of ammoni
Number of molecules: 1 molecule of Nitrogen, 3 molecules of hydrogen, and 2 molecules of ammoni
N2 + 3H2 -> 2NH3
how many are the following:
Number of relative moles: _ mole of nitrogen, _ relative
moles of hydrogen, _ relative moles of ammonia
Number of relative moles: 1 mole of nitrogen, 3 relative
moles of hydrogen, 2 relative moles of ammonia
N2 + 3H2 -> 2NH3
how many are the following:
Mass:
of Nitrogen,
of Hydrogen,
of ammonium
Mass: 28.012g of Nitrogen, 6.0468g of Hydrogen, 34.0588g of ammonium
N2 + 3H2 -> 2NH3
how many are the following:
volume:
of Nitrogen,
of Hydrogen,
of ammonium
Volume: 22.4L of nitrogen, 67.2L of hydrogen, and 44.8L of ammonia
Magnesium metal can react with dry ice (solid CO2) to produce magnesium oxide and carbon. The chemical reaction is shown below
ππ (π )+πΆπ2 (π )βπππ (π )+πΆ (π )
Balance the chemical equation
2ππ (π )+πΆπ2 (π )β2πππ (π )+πΆ (π )
Magnesium metal can react with dry ice (solid CO2) to produce magnesium oxide and carbon. The chemical reaction is shown below
ππ (π )+πΆπ2 (π )βπππ (π )+πΆ (π )
Determine the number of moles carbon produced when 5.0 mole of Mg is used
=2.50 πππππ πΆ
Magnesium metal can react with dry ice (solid CO2) to produce magnesium oxide and carbon. The chemical reaction is shown below
ππ (π )+πΆπ2 (π )βπππ (π )+πΆ (π )
c. If 10.0 moles of MgO must be obtained, how much CO2 is needed
5.0 πππππ πΆπ2
Magnesium metal can react with dry ice (solid CO2) to produce magnesium oxide and carbon. The chemical reaction is shown below
ππ (π )+πΆπ2 (π )βπππ (π )+πΆ (π )
If the amount of Mg in letter b is totally consumed, how much CO2 is required
2.50 πππππ πΆπ2
is an effective cleaning agent commonly found in households. It contains sodium hypochlorite, NaClO, which can produce toxic chlorine gas, Cl2, when combined with muriatic acid (HCl).
bleach
π»ππΆπ+π»πΆπβπ»2π+πΆπ2
Determine the number of moles of Cl2 produced from 15.0g HOCl
0.286 ππππ πΆπ2
π»ππΆπ+π»πΆπβπ»2π+πΆπ2
What mass (g) of HCl is needed to completely react with 4.50 moles HOCl
164.0421π π»πΆπ
is the starting material that is totally consumed when the chemical reaction is completed
limiting reagent or reactant
It limits the amount of product that is formed in a chemical reaction
limiting reagent
In most cases, problems dealing with limiting reagents give the amount (mass or moles) of both reactants
limiting reagent
How many moles of water can we make from 6 moles of hydrogen and 4 moles of oxygen?
2 π»2 (π)+ π2(π)β2π»2π(π)
limiting reagent = H2
Amount of H2O = 6 moles
What mass of iron in grams could be formed from 113g Al and 279g Fe2O3
2 π΄π (π )+ πΉπ2π3 (π )β π΄π2π3 (π )+2 πΉπ (π)
limiting reactant Fe2O3
amount of Fe = 195g
What mass of C3H3N in grams can be made when 21.6g of C3H6 react with 21.6g of NO
4πΆ3π»6(π)+6 ππ(π)β4πΆ3π»3π(π )+6π»2π(π)+π2(π)
25.5π πΆ3π»3π
limiting reagent 21.6g
Consider the reaction between magnesium and carbon dioxide:
ππ (π )+πΆπ2βπππ (π )+πΆ (π )
If 4.50g each of Mg and CO2 were reacted, how many grams of carbon will be produced?
limiting reagent = Mg
carbon produced = 1.11g C
Consider the reaction between magnesium and carbon dioxide:
ππ (π )+πΆπ2βπππ (π )+πΆ (π )
How much of the excess reagent will be left after the reaction?
0.43π πΆπ2
ratio of actual yield/theoretical yield
percent yield
formula of percent yield
actual yield/theoretical yield x 100
amount of product made under ideal conditions, the most possible product you can make (almost never happens), the number you calculate using stoichiometry
theoretical yield
amount of product made during the actual reaction in the laboratory
actual yield
If the amount of carbon obtained in sample exercise 2.2 is 1.00g, determine the percentage yield of the reaction
theoretical yield = 1.11g
90.1%