For Gas volumes and amount of substance, which option best supports this Unit 4.3 objective: (chemistry only) (HT only) Calculate gas volumes from a given volume of a gaseous reactant or product?

The answer is 120 dm3.

The correct option is 120 dm3. This uses Gas Volume at Room Temperature and Pressure because the objective is about (chemistry only) (HT only) Calculate gas volumes from a given volume of a gaseous reactant or product. The reasoning belongs to Gas volumes and amount of substance within Use of amount of substance in relation to volumes of gases (chemistry only) (HT only), 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 chemistry only to keep the answer aligned with AQA GCSE Chemistry 8462 Unit 4.3. The other options are weaker because they either use the wrong formula, the wrong unit, a vague relationship, or the wrong quantitative context.