Stoichiometry

Review

Question 1.

Balance the following equation and choose the quantity which is the sum of the coefficients of the products.

____ SnS2 + ____ HCl          ___ H2SnCl6 + ____ H2S

a)   8b)   5c)   3d)   6e)   7

Question 1.

Balance the following equation and choose the quantity which is the sum of the coefficients of the products.

____ SnS2 + ____ HCl          ___ H2SnCl6 + ____ H2S

a)   8b)   5c)   3d)   6e)   7

1 6 1 2

Question 2.

Balance the following equation. What is the sum of the coefficients of the reactants and products?

____ CoO + ____ O2 ____ Co2O3

a)   9b)   3c)   7d)   6e)   8

Question 2.

Balance the following equation. What is the sum of the coefficients of the reactants and products?

____ CoO + ____ O2 ____ Co2O3

a)   9b)   3c)   7d)   6e)   8

4 1 2

Question 3.

Balance the following equation for the combustion of octane. What is the sum of the coefficients of the reactants and products?

____ C8H18 + ____ O2 ____ CO2 + ____ H2O

a)   30b)   61c)   52d)   43e)   39

Question 3.

Balance the following equation for the combustion of octane. What is the sum of the coefficients of the reactants and products?

____ C8H18 + ____ O2 ____ CO2 + ____ H2O

a)   30b)   61c)   52d)   43e)   39

2 25 16 18

Question 4.

Calculate the number of moles of N2 produced from 0.080 moles of NH3 by the following reaction.

4 NH3 + 6 NO 5 N2 + 6 H2O

a)   0.02b)   0.50c)   0.08d)   0.10e)   0.64

Question 4.

Calculate the number of moles of N2 produced from 0.080 moles of NH3 by the following reaction.

4 NH3 + 6 NO 5 N2 + 6 H2O

a)   0.02b)   0.50c)   0.08d)   0.10e)   0.64

0.080 mol? mol

0.080 mol NH3 x 5 moles N2

4 moles NH3

Question 5.

Phosgene was used in WW1 as a war gas. It reacts with water in the lungs to produce HCl which causes severe lung damage and ultimately leads to death. How many grams of HCl are produced when 11.0 g of CO2 are simultaneously formed?(C = 12.01, O = 16.00, H = 1.008, Cl = 35.45).

COCl2 + H2O 2 HCl + CO2

a)   27.3b)   36.4c)   9.11d)   18.2e)   0.25

Question 5.

Phosgene was used in WW1 as a war gas. It reacts with water in the lungs to produce HCl which causes severe lung damage and ultimately leads to death. How many grams of HCl are produced when 11.0 g of CO2 are simultaneously formed?(C = 12.01, O = 16.00, H = 1.008, Cl = 35.45).

COCl2 + H2O 2 HCl + CO2

a)   27.3b)   36.4c)   9.11d)   18.2e)   0.25

11.0 g CO2 x 1 mol CO2 x 2 mol HCl x 36.458 g

44.01 g 1 mol CO2 1 mol

Question 6.Calculate the number of moles of Na2CS3 produced from 0.6 moles of CS2 by the following reaction.

3 CS2 + 6 NaOH 2 Na2CS3 + Na2CO3 + 3 H2O

a)   0.2b)   0.4c)   0.8d)   0.6e)   0.9

Question 6.Calculate the number of moles of Na2CS3 produced from 0.6 moles of CS2 by the following reaction.

3 CS2 + 6 NaOH 2 Na2CS3 + Na2CO3 + 3 H2O

a)   0.2b)   0.4c)   0.8d)   0.6e)   0.9

0.6 mol CS2 x 2 moles N2

3 moles NH3

Question 7.

A sample of lime, CaO, weighing 69 g was prepared by heating 131 g of limestone, CaCO3. What was the percent yield of the reaction?(Atomic weights: Ca = 40.08, C = 12.01, O = 16.00).

CaCO3 CaO + CO2

a)   97b)   73c)   85d)   94e)   91

Question 7.

A sample of lime, CaO, weighing 69 g was prepared by heating 131 g of limestone, CaCO3. What was the percent yield of the reaction?(Atomic weights: Ca = 40.08, C = 12.01, O = 16.00). CaCO3 CaO + CO2

a)   97b)   73c)   85d)   94e)   91

131 g CaCO3 x 1 mol CaCO3 x 1 mol CaO x 56.08 g

100.09 g 1 mol CaCO3 1 mol

= 73.4 g Theoretical yield

% yield =69 g /73.4 g x 100

Question 8.

100. mL of hydrogen gas at STP would contain how many moles?

a)   0.00446b)   0.050c)   0.446d)   4.46e)   224

Question 8.

100. mL of hydrogen gas at STP would contain how many moles?

a)   0.00446b)   0.050c)   0.446d)   4.46e)   224

100. mL x 1 L x 1 mol

1000 mL 22.4 L

Question 9.

For the reaction:

N2H4 + 3 O2 2 H2O + NO2 + 400 kJ

What is the energy released when 4.60 g if NO2

is produced?

a)   40.0 kJb)   18.0 kJc)   120.0 kJd)   160.0 kJ

Question 9.

For the reaction:

N2H4 + 3 O2 2 H2O + NO2 + 400 kJ

What is the energy released when 4.60 g if NO2

is produced?

a)   40.0 kJb)   18.0 kJc)   120.0 kJd)   160.0 kJ

4.60 g NO2 x 1 mol NO2 x 400 kJ

46.0 g 1 mol NO2

Question 10.

What is the mass of a sample of C3H8 gas of it occupies 100. mL at STP?

a)   0.196b)   0.509c)   5.09d)   19.6e)   196

Question 10.

What is the mass of a sample of C3H8 gas of it occupies 100. mL at STP?

a)   0.196b)   0.509c)   5.09d)   19.6e)   196

100. mL x 1 L x 1 mol x 44.0 g

1000 mL 22.4 L 1 mol