Unit 7 Test Review

2H₂ + O₂ → 2H₂O

How many moles of hydrogen are consumed if 8 moles O₂ are used?

• 2 mol

• 4 mol

• 16 mol

• 18 mol

In the lab, a student produces 17.5 grams of a product, when the theoretical amount of the product was calculated to be 24.8 grams. What is the student’s percent yield?

• 35.7%

• 70.6%

• 98.1%

• 1142%

2Na + 2H₂O → 2NaOH + H₂

How many grams of NaOH are produced if 56 g of Na are available?

• 5.5 g

• 26 g

• 97 g

• 110 g

Cl₂ + 2KBr → Br₂ + 2KCl

How many molecules of potassium bromide are needed to react with 25.0 g of chlorine?

• 749 molecules

• 4.25x10²³ molecules

• 4.79x10²² molecules

• 81.4 molecules

CH₄ + 2H₂O → CO₂ + 4H₂

How many grams of CO₂ will form when 20.0 g of CH₄ reacts with 15.0 g of H₂O?

• 65.3 g

• 18.3 g

• 54.8 g

• 15.0 g

Tags

NGSS.HS-PS1-7

3Mg + Fe₂O₃ → 3MgO + 2Fe

How many grams of Mg are required to produce 1.45x10²² molecules of Fe?

• 0.878 g

• 2.50 g

• 23.6 g

• 55.1 g

4NH₃ + 6NO → 5N₂ + 6H₂O

What is the limiting reactant if 5 moles of NH₃ react with 10 moles of NO?

• NH₃

• NO

• N₂

• H₂O

CH₄ + 2O₂ → CO₂ + 2H₂O

How many moles of water are produced from the combustion of 87.5 g of CH₄?

• 1.37 mol

• 2.75 mol

• 5.45 mol

• 10.9 mol

2Fe + 3Cl₂ → 2FeCl₃

How many grams of FeCl₃ can form if 8.43 g of Fe are reacted?

• 14.8 g

• 24.5 g

• 13.7 g

• 49.9 g

In a lab, a scientist calculated that he should produce 22.5 grams of product in his experiment. When he is finished collecting his product, it weighs 12.6 grams. What is his percent yield?

• 56.0%

• 0.85%

• 11.9%

• 179%