A-LevelChemistryReaction kinetics9701/12 · May/June 2010 · Q131 Mark
Na2S2O3 reacts with dilute HCl to give a pale yellow precipitate. If 1 cm³ of 0.1 mol dm⁻³ HCl is added to 10 cm³ of 0.02 mol dm⁻³ Na2S2O3 the precipitate forms slowly. If the experiment is repeated with 1 cm³ of 0.1 mol dm⁻³ HCl and 10 cm³ of 0.05 mol dm⁻³ Na2S2O3 the precipitate forms more quickly. Why is this?
AThe activation energy of the reaction is lower when 0.05 mol dm⁻³ Na2S2O3 is used.
BThe reaction proceeds by a different pathway when 0.05 mol dm⁻³ Na2S2O3 is used.
CThe collisions between reactant particles are more violent when 0.05 mol dm⁻³ Na2S2O3 is used.
DThe reactant particles collide more frequently when 0.05 mol dm⁻³ Na2S2O3 is used.
✓ Correct answer
D: The reactant particles collide more frequently when 0.05 mol dm⁻³ Na2S2O3 is used.
Practise more questions on this topic
Oracle Prep sorts past-paper questions by topic, so you can drill Reaction kinetics and see which topics are most likely to come up next.
Sign up free →