Unit 5 Review

For the reaction C + 2 H₂ → CH₄, how many moles of hydrogen (H₂) are required to produce 10 mol of methane (CH₄)?

• 2 mol

• 4 mol

• 5 mol

• 20 mol

The equation shows a balanced chemical reaction.

Fe₂O₃ + 1 Al → Al₂O₃ + 2 Fe

How many moles of aluminum oxide (Al₂O₃) can be produced from 4.0 mol of aluminum?

• 2.0 mol

• 4.0 mol

• 6.0 mol

• 8.0 mol

One mole is equal to ...

• 1.5 x 10²⁴ molecules

• 3.14 x 10²³ molecules

• 6.02 x 10²⁴ molecules

• 6.02 x 10²³ molecules

What is the molar mass of copper (Cu)?

• 63.55 g/mol
• 62.00 g/mol
• 65.38 g/mol
• 60.10 g/mol

What is the percent of nitrogen contained in ammonium nitrate, NH₄NO₃?

• 25.00%
• 10.50%
• 50.00%
• 34.96%

What are the coefficients needed to balance this chemical reaction to show that matter is conserved?

Fe + Cl₂ → FeCl₃

• 1 Fe + 2 Cl2 → 1 FeCl3
• 3 Fe + 2 Cl2 → 3 FeCl3
• 2 Fe + 1 Cl2 → 2 FeCl2
• 2 Fe + 3 Cl2 → 2 FeCl3

How many molecules are in a drop of water containing 0.00390 moles?

• 2.35 x 10²¹ molecules

• 1.50 x 10²⁰ molecules

• 3.00 x 10²² molecules

• 5.67 x 10¹⁹ molecules

How many atoms of helium (He) are in a 0.25 g sample?

• 1.5 x 10²² atoms

• 3.8 x 10²² atoms

• 7.5 x 10²¹ atoms

• 2.0 x 10²³ atoms

What is the total mass of 3 moles of NaOH?

• 90 g
• 120 g
• 100 g
• 150 g