Grade 10 · Chemistry

Grade 10 Chemistry — Moles and molar mass questions and answers

The chemistry unit US students search most. Written in American English for students, parents, and teachers in the United States.

Practice quiz

Open a card to see the answer. These are original practice items for US elementary students — not a state test copy.

1. One mole contains

Answer: 6.022 × 10²³ particles (Avogadro’s number)

A mole is a counting unit.

2. Molar mass of H₂O is about

Answer: 18 g/mol

2(1) + 16 = 18.

3. Molar mass of CO₂ is about

Answer: 44 g/mol

12 + 32 = 44.

4. Moles =

Answer: mass (g) / molar mass (g/mol)

n = m/M.

5. 36 g of water is how many moles?

Answer: 2 mol

36/18 = 2.

6. At STP, 1 mole of an ideal gas occupies about

Answer: 22.4 L

This is a common US chemistry search.

7. The molar mass of NaCl is about

Answer: 58.5 g/mol

23 + 35.5 ≈ 58.5.

8. A balanced equation’s coefficients tell you

Answer: mole ratios of reactants and products

2H₂ + O₂ → 2H₂O means 2 mol H₂ per 1 mol O₂.