Limiting Reagents And Percentage Yield Worksheet Answers

Limiting Reagents and Percentage Yield Worksheet

1.
Consider the reaction

I2O5(g) + 5 CO(g) -------> 5 CO2(g) + I2(g)

a) 80.0 grams of iodine(V) oxide, I2O5, reacts with 28.0 grams of carbon monoxide, CO. Determine the mass of iodine I2, which could be produced?
80 g I2O5
1 mol I2O5
1 mol I2

1
333.8 g I2O5
1 mol I2O5

28 g CO
1 mol CO
1 mol I2
253.8 g I2

1
28 g CO
5 mol CO
1 mol I2

b) If, in the above situation, only 0.160 moles, of iodine, I2 was produced. i) what mass of iodine was produced?
0.160 mol I2
253.8 g I2
= 40.6 g I2

1 mol I2

ii) what percentage yield of iodine was produc ed.
40.6 g I2 x 100 =
79.9 %
50.8 g I2

2.

Zinc and sulphur react to form zinc sulphide according to the equation.

Zn + S  ZnS

If 25.0 g of zinc and 30.0 g of sulphur are mixed, a) Which chemical is the limiting reactant?
25.0 g Zn
1 mol Zn
1 mol ZnS
=.382 mol ZnS

1
65.41 g Zn
1 mol Zn

30.0 g S
1 mol S
1 mol ZnS
=.934mol ZnS

1
32.1g S
1 mol S

b) How many grams of ZnS will be formed?
.382 mol ZnS
97.51 g ZnS
= 37.2 g ZnS

1 mol ZnS

c) How many grams of the excess reactant will remain after the reaction is over?
.934mol ZnS -.382 mol ZnS= .552mol ZnS

.552 mol ZnS
1 mol S
32.1g S
= 17.7g S

1 mol ZnS
1 mol S

3.

Which element is in excess when 3.00 grams of Mg is ignited in 2.20 grams of pure oxygen?
What mass is in excess? What mass of MgO is formed?
2Mg + O2  2MgO
3.00 g Mg
1 mol Mg
2 mol MgO
40.3 g MgO
= 4.98 g MgO 1
24.3 g Mg
2 mol Mg
1 mol MgO

2.20 g O2
1 mol O2
2 mol MgO
40.3 g MgO
= 5.54 g MgO 1
32.0 g O2
1mol O2
1 mol MgO

4.
5.54 g MgO - 4.98 g MgO = .561 g MgO

How many grams of Al2S3 are formed when 5.00 grams of Al is heated with 10.0 grams S?
2Al + 3S  Al2S3
5.00 g Al
1 mol Al
1 mol Al2S3
150.17 g Al2S3
= 13.9 g Al2S3 1
26.98 g Al
2 mol Al
1 mol Al2S3

10.0 g