Stoichiometric Calculations MDCAT MCQs with Answers

The molar mass of H₂O is:
A) 16 g/mol
B) 18 g/mol
C) 20 g/mol
D) 22 g/mol

In the reaction 2H₂ + O₂ → 2H₂O, how many grams of water are formed from 2 moles of H₂?
A) 18 g
B) 36 g
C) 54 g
D) 72 g

How many moles of O₂ are needed to completely combust 5 moles of CH₄?
A) 5 moles
B) 10 moles
C) 15 moles
D) 20 moles

What is the mass of CO₂ produced when 88 g of C₃H₈ burns completely?
A) 176 g
B) 264 g
C) 132 g
D) 90 g

If 4 moles of Al react with O₂ to form Al₂O₃, how many moles of Al₂O₃ are produced?
A) 1 mole
B) 2 moles
C) 3 moles
D) 4 moles

How many grams of NaCl are produced from 1 mole of NaOH reacting with HCl?
A) 40 g
B) 58.5 g
C) 36.5 g
D) 60 g

What is the volume of CO₂ gas produced at STP from the complete combustion of 2 moles of CH₄?
A) 22.4 L
B) 44.8 L
C) 89.6 L
D) 33.6 L

In the reaction N₂ + 3H₂ → 2NH₃, how many grams of NH₃ are formed from 5 moles of H₂?
A) 34 g
B) 85 g
C) 170 g
D) 51 g

What is the molar mass of CaCO₃?
A) 100 g/mol
B) 120 g/mol
C) 140 g/mol
D) 160 g/mol

In the reaction 2KClO₃ → 2KCl + 3O₂, how many grams of O₂ are produced from 245 g of KClO₃?
A) 96 g
B) 48 g
C) 128 g
D) 32 g

How many grams of H₂ are required to produce 36 g of H₂O in 2H₂ + O₂ → 2H₂O?
A) 2 g
B) 4 g
C) 8 g
D) 16 g

How many liters of O₂ gas are needed to react with 11.2 L of CH₄ at STP in CH₄ + 2O₂ → CO₂ + 2H₂O?
A) 11.2 L
B) 22.4 L
C) 33.6 L
D) 44.8 L

What is the empirical formula of a compound that contains 40% sulfur and 60% oxygen by mass?
A) SO
B) SO₂
C) S₂O₃
D) S₃O₄

How many moles of water are produced when 1 mole of ethane combusts completely?
A) 1 mole
B) 2 moles
C) 3 moles
D) 4 moles

What is the theoretical yield of CO₂ when 50 g of C reacts with O₂ in excess?
A) 132 g
B) 180 g
C) 88 g
D) 100 g

If 3 moles of N₂ and 9 moles of H₂ react, what is the maximum number of moles of NH₃ that can be formed in N₂ + 3H₂ → 2NH₃?
A) 2 moles
B) 4 moles
C) 6 moles
D) 9 moles

How many moles of Na₂CO₃ are needed to completely neutralize 2 moles of HCl?
A) 1 mole
B) 2 moles
C) 3 moles
D) 4 moles

What is the limiting reactant when 10 g of H₂ react with 20 g of O₂ to produce H₂O?
A) H₂
B) O₂
C) H₂O
D) None

How many grams of NaOH are required to prepare 2 moles of NaOH solution?
A) 20 g
B) 40 g
C) 80 g
D) 120 g

How many grams of oxygen are needed to completely combust 1 mole of CH₄?
A) 16 g
B) 32 g
C) 48 g
D) 64 g