Unit 5 Review

Determine the % composition of Potassium in the following copound KMnO₄

• 14.8%

• 34.8%

• 24.7%

• 40.5%

How much mass is in a 3.25-mole sample of NH₄OH

• 10.8 g

• 34.0 g

• 114 g

• 35.1 g

Tags

NGSS.HS-PS1-7

What percentage of water is present in CuSO₄ * 5H₂O

• 15%

• 22.5%

• 36%

• 50%

The empirical formula of a compound is CH2. its molecular mass is 70 g/mol. What is its molecular formula?

• C₂H₄

• C₅H₁₀

• C₆H₁₂

• C₈H₁₆

A compound is 64.9% carbon, 13.5% hydrogen, and 21.6% oxygen. Its molecular mass is 74 g/mol. What is its molecular formula?

• C₄H₁₀O

• C₅H₁₀

• C₂H₄O₂

• None of these

What is the molar mass of Fe₃(PO₄)₂

• 823.8g/mol
• 357.5 g/mol
• 455.6g/mol
• 86.3g/mol

6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂ 
What is the total number of moles of water needed to make 2.5 moles of C₆H₁₂O₆?

• 2.5
• 6
• 12
• 15

Tags

NGSS.HS-PS1-7

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation?   P₄O₁₀ + 6 H₂O --> 4 H₃PO₄ 

• 6:4
• 4:6
• 1:3
• 3:1

Tags

NGSS.HS-PS1-7

Using the following equation:
Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
How many moles of iron can be made from  6 moles H₂? 

• 4 moles Fe
• 6 moles Fe
• 9 moles Fe
• 2 moles Fe

Tags

NGSS.HS-PS1-7

Mole ratios are obtained from the

• balanced chemical equation
• periodic table
• molar mass