Stoichiometry Practice Problems Set #3

2 KClO₃ → 2 KCl + 3 O₂
How many moles of oxygen are produced when 6.7 moles of KClO₃ decompose completely?

• 6.7 mol
• 1.0 mol
• 10.1 mol
• 4.5 mol

Tags

NGSS.HS-PS1-7

A chemist interested in the efficiency of a chemical reaction would calculate the

• mole ratio
• rate of reaction
• percent yield
• energy released

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

CH₄ + 2 O₂ → CO₂ + 2 H₂O
How many moles of carbon dioxide are produced from the combustion of 110 g of CH₄?

• 13.7 mol
• 2.75 mol
• 6.11 mol
• 6.85 mol

Tags

NGSS.HS-PS1-7

Calculate the mass (in g) of water produced from the complete combustion of 1.000 gallon (3.800 L) of gasoline (C₈H₁₈). The density of gasoline is 0.7900 g/mL.

• 8.522 X 10³ g H₂O

• 4.261 X 10³ g H₂O

• 9.737 X 10⁵ g H₂O

• 7.678 X 10³ g H₂O

Consider the reaction of magnesium hydroxide with phosphoric acid. 3Mg(OH)2 + 2H3PO4 H Mg3(PO4)2 + 6H2O (a) Calculate the mass of Mg3(PO4)2 that will be formed (assuming a 100% yield) from the reaction of 45.0 g of 92.5% Mg(OH)2 with an excess of H3PO4

• 6.97 g Mg₃(PO₄)₂

• 20.9 g Mg₃(PO₄)₂

• 62.7 g Mg₃(PO₄)₂

• 1.39 g Mg₃(PO₄)₂