WorksheetsUnderstanding Limiting and Excess Reactants
Total questions: 9
Worksheet time: 29mins
1-8.
Answer the questions below after watching the video
What determines the maximum number of cheeseburgers that can be made?
The total ingredients available
The amount of cheese
The number of buns
The quantity of meat
What happens when the limiting reactant is completely used up?
The reaction continues indefinitely
More product can still be formed
The reaction stops and no more product forms
Excess reactants disappear
How many bread rolls can be made with the available ingredients in the example?
15
10
20
5
What is a common misconception about the limiting reactant?
It cannot be determined without a chemical reaction
It is always a liquid
It is the reactant present in the smallest quantity
It is always a solid
In the NH3 production example, which reactant is limiting?
O2
N2
H2
NH3
How many moles of NH3 can be produced in the given chemical reaction?
1.8 moles
3.2 moles
3.6 moles
5.4 moles
What is left over as the excess reactant in the NH3 production example?
N2
H2
O2
NH3
How much of the excess reactant is left over after the reaction?
1.8 moles
3.2 moles
5.4 moles
1.4 moles
In the image, which reactant is limiting?
The white molecules, because there are extra.
The black atoms, because they are completely used up.
The white molecules, because they are completely used up.
The black atoms, because there are extra.
3 Mg + 1 Fe2O3 → 3 MgO + 2 Fe
Identify the mole ratios for the following pairs:
(a) Mg : (b) Fe
(c) Fe2O3 : (d) Fe
1 Fe2O3 : (e) MgO
How many of each type of atom are in Na2SO4?
(a) Na
(b) S
(c) O
(d) atoms total
The theoretical yield of a chemical reaction is:
The maximum amount of product that can be produced as predicted by stoichiometry.
The amount of product actually obtained from the reaction.
Always equal to the actual yield.
Dependent on the reaction conditions such as temperature and pressure.
How do you determine the excess reactant in a chemical reaction?
By calculating which reactant has the highest molar mass.
By identifying the reactant that has the smallest coefficient in the balanced equation.
By calculating the amount of product formed from each reactant and identifying the reactant that forms the least amount of product.
By identifying the reactant that remains after the limiting reactant is completely used up.
When two substances react to form products, what is the reactant that is used up first called?
explosive reactant
true reactant
limiting reactant
excess reactant
