Practise Edexcel IGCSE Chemistry investigation variables by choosing what to keep constant, including concentration, volume, mass and temperature.
A student investigates the effect of temperature on the rate of reaction between two solutions, A and B . When the reaction occurs, the mixture turns from colourless to blue.
This is the student's method.
- pour 25 cm3 of solution A into a conical flask
- add solution B and measure the temperature of the mixture
- record the time taken for the mixture to turn blue
The student repeats this method at different temperatures.
Give two variables that the student needs to keep constant in this investigation.
1
2
Any two from
M1 concentration of solution A
M2 concentration of solution B
M3 volume of solution B
ALLOW amount of solution B
Ignore apparatus