The mole
15 review questions with answers for The mole. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Number of particles in one mole?
- 6.02 × 10²³Right answer
- 6.02 × 10²²
- 3.01 × 10²³
- 1.00 × 10²³
What this set covers
The mole as a counting unit, built up from the Avogadro constant, relative formula mass and moles = mass ÷ Mr. Gas volume at room temperature and pressure, concentration in g dm⁻³ and empirical formulas follow.
- Common mix-up
- Students often confuse empirical and molecular formulas: C₂H₄ has the empirical formula CH₂, the simplest whole-number ratio, even though each molecule really contains two carbon atoms.
- Review tip
- Write the mass, moles and Mr triangle from memory, then use it to solve the 9 g of water and 88 g of CO₂ questions without looking at the answers.
All 15 questions and answers
Number of particles in one mole?
Answer: 6.02 × 10²³
Relative formula mass of CO₂ (C = 12, O = 16)?
Answer: 44
Relative formula mass of NaOH (Na = 23, O = 16, H = 1)?
Answer: 40
Number of atoms in one molecule of H₂SO₄?
Answer: 7
Moles = mass ÷ …?
Answer: Mr
Amount in 24 g of magnesium (Ar = 24)?
Answer: 1 mol
Amount in 9 g of water (Mr = 18)?
Answer: 0.5 mol
Amount of CO₂ in 88 g (Mr = 44)?
Answer: 2 mol
Mass of 2 mol of NaCl (Mr = 58.5)?
Answer: 117 g
Mass of CO₂ formed when 6 g of carbon burns (C = 12, CO₂ = 44)?
Answer: 22 g
Volume of one mole of any gas at room temperature and pressure?
Answer: 24 dm³
Number of cm³ in 1 dm³?
Answer: 1000 cm³
Concentration when 10 g of salt is dissolved to make 0.50 dm³ of solution?
Answer: 20 g dm⁻³
Formula showing the simplest whole-number ratio of atoms in a compound?
Answer: Empirical formula
Empirical formula of C₂H₄?
Answer: CH₂
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.