{{asɛmtiNe Ɔkyerɛwfo}} | Nhomakorabea | Nneɛma a ɛma wotumi yɛ ade

1

null null cm_³

2

Which two variables should the student keep the same to make the investigation a fair test? Tick two boxes.

1

2

Mmuae Afoforo a Wobɛpaw:

solid

sulfur

6

Plan an investigation to show how the concentration of the sodium thiosulfate solution affects the rate of the reaction with dilute hydrochloric acid.

Your plan should give valid results.

method

• measure volume of sodium thiosulfate

• place sodium thiosulfate in

• measure volume of hydrochloric acid

• place on

• add hydrochloric acid to (conical) flask

• swirl

• start

• measure time for cross to become no longer visible

• repeat for different concentrations of sodium thiosulfate

control variables

• of hydrochloric acid

• volume of hydrochloric acid

• of sodium thiosulfate solution

Mmuae Afoforo a Wobɛpaw:

volume

conical flask

cross

stopwatch

measuring cylinder

concentration

1

2025-2026 GCSE Rates of reaction

2025-2026 GCSE Rates of reaction

Which two variables should the student keep the same to make the investigation a fair test? Tick two boxes.

Which two variables should the student keep the same to make the investigation a fair test? Tick two boxes.