Calculate the number of moles in 50 grams of water (H2O). The relative formula mass (Mr) of water is 18 g/mol.

The calculated answer is 2.78 mol.

This uses Moles From Mass because the objective is about (HT only) Explain that one mole of a substance contains the same number of stated particles as one mole of any other substance. This formula choice variant asks students to separate HT only from similar Unit 4.3 calculation steps. The reasoning belongs to Moles (HT only) within Use of amount of substance in relation to masses of pure substances, so it should not be confused with nearby quantitative ideas such as mass, moles, concentration, yield, atom economy, or gas volume unless those are named in the objective. Use the focus term HT only to keep the answer aligned with AQA GCSE Chemistry 8462 Unit 4.3.