10.8 g of aluminium reacts with excess oxygen to form aluminium oxide: 4Al + 3O2 → 2Al2O3. What is the theoretical yield of aluminium oxide? (Ar of Al = 27.0 and Mr of Al2O3 = 102)
40.8 g
20.4 g
10.2 g
In a reaction, the theoretical yield was 80 g but the actual yield was 60 g. What was the percentage yield?
75%
133%
50%
What happens to the percentage yield if a side reaction occurs?
It increases
It stays the same
It decreases
What is the theoretical yield of a product?
The mass of product made in an experiment
The maximum possible mass of product that could be made in a reaction
The actual mass of product made in a reaction
6.0 g of carbon reacts completely with 16.0 g of oxygen. What is the maximum mass of carbon dioxide that could form?
10.0 g
22.0 g
11.0 g
What happens to the percentage yield if some product stays on the filter paper after filtration?
Sulfur trioxide is made by reacting sulfur dioxide with oxygen: 2SO2 + O2 → 2SO3. What is the atom economy of this reaction?
100%
66.7%
How can the atom economy of a particular reaction be improved?
Use a greater mass of reactant
Heat the reaction mixture more strongly
Find a use for one of the other products
Hydrogen can be made from the electrolysis of water: H2O → H2 + ½O2. What is the atom economy of this process? (Relative formula masses: H2O = 18.0 and H2 = 2.0)
11.1%
5.56%
Which statement is correct?
If the atom economy is 100%, the percentage yield must also be 100%
The atom economy and percentage yield do not depend on one another
If the atom economy is 100%, the theoretical yield must also be 100%