Gas Stoichiometry Review

Gas Stoichiometry Review

1.  Given:

CaCO3(s) ® CO2(g) + CaO(s)

How many grams of calcium carbonate will be needed to form 4.29 liters of carbon dioxide if the reaction occurs at 1.00 atm and 300 K?

R = 0.08206 atm L mol-1 K-1 P = 1.00 atm V = 4.29 L n= ? T = 300 K

0.08206 atm L mol-1 K-1 = 1.00 atm (4.29 L)

n (300 K)

n = 0.174262735 mol CO2

0.174262735 mol CO2 x 1 mol CaCO3 x 100.09 g CaCO3 = 17.4 g CaCO3

1 1 mol CO2 1 mol CaCO3

2.  If 50.2 liters of oxygen are consumed during the combustion reaction of benzene (C6H6) at STP, how many liters of water vapor will be formed?

2C6H6 + 15O2 ® 12CO2 + 6H2O

50.2 L O2 x 1 mol O2 x 6 mol H2O x 22.4 L H2O = 20.1 L H2O

1 22.4 L O2 15 mol O2 1 mol H2O

3.  Given the unbalanced equation:

4 NH3(g) + 5 O2(g) ® 4 NO(g) + 6 H2O(g)

How many grams of NO will be produced when 26.8 L of water vapor are produced at STP?

26.8 L H2O x 1 mol H2O x 4 mol NO x 30.01 g NO = 23.9 g NO

1 22.4 L H2O 6 mol H2O 1 mol NO

4.  If magnesium is added to hydrochloric acid (HCl), hydrogen gas and magnesium chloride are made. If 3.46g of HCl is used, what volume of hydrogen gas will be produced at 1.4 atm and 25°C?

Mg + 2HCl ® H2 + MgCl2

3.46 g HCl x 1 mol HCl x 1 mol H2 = 0.047449259 mol H2

1 36.46 g HCl 2 mol HCl

R = 0.08206 atm L mol-1 K-1 P = 1.4 atm V = ? n= 0.047449259 mol T = 25 °C

25 °C + 273.15 = 298.15 K

0.08206 atm L mol-1 K-1 = 1.4 atm (V) V = 0.829 L H2

6.111 mol (298.15 K)

5.  How many liters of CO2 are made if 9.5 L of acetylene (C2H2) react in a combustion reaction with 13.7 L of oxygen at STP?

2C2H2 + 5O2 ® 4CO2 + 2H2O

9.5 L C2H2 x 1 mol C2H2 x 4 mol CO2 x 22.4 L CO2 = 19.0 L CO2

1 22.4 L C2H2 2 mol C2H2 1 mol CO2

13.7 L O2 x 1 mol O2 x 4 mol CO2 x 22.4 L CO2 = 11.0 L H2O

1 22.4 L O2 5 mol O2 1 mol CO2