WorksheetsChemical calculations - yields
Total questions: 14
Worksheet time: 15mins
If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the
theoretical yield
mole ratio
actual yield
percentage yield
Balance the equation below
C2H6 + O2 --> CO2 + H2O
1:1:1:1
1:2:1:2
1:3:2:3
2:7:4:6
2:9:5:7
What is the ratio of ethane (C2H6) to water (H2O)?
2C2H6 + 7O2 --> 4CO2 + 6H2O
Pick TWO answers
2:6
1:2
1:3
1:4
2:4
How many moles of water can you produce from 1 mole of ethane?
2C2H6 + 7O2 --> 4CO2 + 6H2O
1
2
3
4
6
What is the molar mass (Mr) of ethene?
2C2H6 + 7O2 --> 4CO2 + 6H2O
12
18
30
44
60
What is the molar mass (Mr) of water?
2C2H6 + 7O2 --> 4CO2 + 6H2O
12
18
30
44
60
How many moles are in 90g of ethane?
2C2H6 + 7O2 --> 4CO2 + 6H2O
1
2
3
4
6
What is the mass of 5 moles of water?
2C2H6 + 7O2 --> 4CO2 + 6H2O
12
18
30
60
90
How would you work out the theoretical yield of water if you start with 90g ethane (C2H6).
C2H6 + O2 --> CO2 + H2O
Balance the equation
find the mole ratio of ethane to water
calculate the Mr of ethane
calculate the moles of ethane
Use the mole ratio to find the moles of water
calculate the Mr of water
calculate the mass of water
Balance the equation
find the mole ratio of ethane to water
Use the mole ratio to work out the mass of water
calculate the Mr of ethane
calculate the moles of ethane
Use the mole ratio to find the moles of water
calculate the Mr of water
calculate the mass of water
Use mass =moles x Mr
then moles = concentration x volume
Balance the equation
calculate the Mr of ethane
calculate the moles of ethane
calculate the Mr of water
calculate the mass of water
Work out the theoretical yield of water if you start with 90g ethane (C2H6).
C2H6 + O2 --> CO2 + H2O
180g
162g
90g
27g
54g
