Gas
Stoichiometry Notes
1.) Use the Ideal Gas Law Equation to solve for V. Let n = 1 mole at STP.
The answer is known as the molar (because it comes from 1 mole) volume of a gas. One
mole of any gas at STP will have this volume. What is your answer? _____________
2.) Mole definitions … use your memory or notes to answer the following:
1 mole = _____________________ things (atoms, ions, molecules, etc)
(BTW, this number is called ____________________ number)
1 mole = _____________________ (taken from the Periodic Table)
1 mole = _____________________ of any gas at STP
(this is the number/answer you calculated in #1 above)
3.) Sample mole problems … use the above three definition to solve each of the following:
a. 2.54 moles = __________________ atoms
b. 16.34 g of Fe = _________________ moles Fe
c.
12.2 L of H2 at STP = ________________ moles H2
d. 1.06 X 1020 molecules = _________________ moles
e. 0.125 moles N2 = _________________ g
f.
6.25 moles CO2 = __________________ L CO2 at STP
4.) Stoichiometry Problems require the following four steps …
a. A balanced equation representing the facts
b. Changing any mass / volume to moles
c. Applying the mole ratio
d. Changing moles to mass / volume
5.) Use the above rules to solve these simple stoichiometry problems.
Zinc metal reacts with hydrochloric acid to form hydrogen gas and zinc chloride.
a. How many grams of hydrogen can be produced by 2.25 g of Zn reacting with
excess hydrochloric acid?
b. How many liters of hydrogen at STP will be formed in the same reaction?
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c.
How many liters of oxygen at STP will form from the decomposition of 22.2 g of
water?
d. How many liters of carbon dioxide gas will be formed when 65.4 g of calcium
carbonate reacts with excess hydrochloric acid?
e. How many grams of liquid water can be formed from 8.68 L of hydrogen gas at
STP?
f.
How many liters of ammonia gas will be formed when 19.5 L of hydrogen gas at
STP reacts with an excess of nitrogen?
g. Hydrogen peroxide (H2O2) can be used as a source of oxygen gas. How many
grams of hydrogen peroxide would need to decompose if exactly 1.00 L of
oxygen gas at STP was required?
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