WorksheetsLimiting Reactants and Stoichiometry
Total questions: 26
Worksheet time: 44mins
What is the definition of a limiting reactant in a chemical reaction?
The substance that is completely used up first in a reaction.
The substance that is left over after a reaction.
The substance that controls the rate of the reaction.
The substance that is used to catalyze the reaction.
In the reaction 2H2+O2→2H2O , if you start with 3 moles of H2 and 1 mole of O2 , which is the limiting reactant?
H2
O2
Both are limiting.
Neither is limiting.
Which is an attribute of the excess reactant in a chemical reaction?
It increases the reaction rate.
It is completely used up during the reaction.
It remains after the limiting reactant is used up.
It decreases the yield of the product.
Calculate the amount of water produced when 4 moles of H2 react with 4 moles of O2 in the reaction 2H2+O2→2H2O .
4 moles of H2O
8 moles of H2O
2 moles of H2O
6 moles of H2O
If 5 moles of nitrogen react with 15 moles of hydrogen according to the equation N2+3H2→2NH3 , how many moles of ammonia are produced?
5 moles
10 moles
15 moles
20 moles
In a reaction where A+2B→C , you start with 4 moles of A and 10 moles of B. How many moles of B will be left unreacted after the reaction goes to completion?
2 moles
4 moles
6 moles
8 moles
Given the reaction 3Fe+4O2→2Fe2O3 , if you start with 10.0 moles of Fe and 6.0 moles of O2 , which reactant is in excess and by how much?
Fe is in excess by 5.5 moles.
O2 is in excess by 2 moles.
Fe is in excess by 4.5 mole.
O2 is in excess by 1 mole.
For the balanced chemical equation 2A+3B→4C , if 10. moles of A react with 10. moles of B, how many moles of C will be produced?
10. moles
13 moles
17 moles
20. moles
In the reaction 6K+N2→2K3N , if 12 moles of K and 10. moles of N2 are used, how many moles of K3N are formed?
4.0 moles
6.0 moles
8.0 moles
10. moles
Given the equation 2X+Y→Z , if you start with 50 grams of X and 20 grams of Y, and the molar mass of X is 10 g/mol and Y is 5 g/mol, which is the limiting reactant?
X
Y
Both are limiting.
Neither is limiting.
In a reaction where 3Mg+N2→Mg3N2 , you start with 15 grams of Mg and 10 grams of N2. The molar mass of Mg is 24.3 g/mol and N2 is 28 g/mol. How many grams of Mg3N2 can be produced?
21 grams
25 grams
30 grams
35 grams
For the reaction 2S+3T→4U , if you start with 200 grams of S and 300 grams of T, and the molar mass of S is 32 g/mol and T is 48 g/mol, identify the limiting reactant.
S
T
Both are limiting.
Neither is limiting.
A reaction 2A+4B→3C is set up with 8 moles of A and 8 moles of B. Calculate the amount of C produced and identify the excess reactant.
12 moles of C, A is in excess
12 moles of C, B is in excess
6 moles of C, A is in excess
6 moles of C, B is in excess
Use the equation 2 Al + 3 Cl2 ---> 2 AlCl3. If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.
AlCl3
Cl2
Al
1 Cheese + 2 Bread --> 1 grilled cheese
How many grilled cheeses can you make with 26 slices of bread and 14 pieces of cheese?
14
13
26
Which element has an abundance of 39.04% in the compound sodium phosphate, Na3PO4
Na
P
O
None of the above
Which statement best describes the excess reactant in a chemical reaction?
It remains after the limiting reactant is used up.
It is always present in equal amounts as the limiting reactant.
It is completely consumed during the reaction.
It determines the amount of product formed.
(a) ----> (b)
The limiting and excess reactant will be on the (c) side of the equation.
Students held a four-mole strip of magnesium over a flame until a combustion began. Students were provided the balanced chemical reaction for the combustion of magnesium and asked to describe the limiting reactant.
2Mg + O2 → 2MgO
Student 1
Student 2
Student 3
Student 4
Identify the limiting and excess reactants in the reaction shown.
N2 is limiting and H2 is excess.
H2 is limiting and N2 is excess.
NH3 is both limiting and excess.
There is no limiting reactant.
