Edexcel IGCSE Chemistry 3.11 Dynamic equilibrium
Practise explaining rate changes with collision theory, linking particle energy, surface area, concentration and graph shape.
- Syllabus
- First assessment 2019
- Course
- Chemistry 4CH1
Exam points
- link higher temperature to more particles exceeding activation energy and more successful collisions
- explain greater surface area using more frequent collisions per unit time
- interpret curve shape from changing concentration and decreasing gradient as reactants are used up
3.11 Collision theory and reaction rate question 1
[Maximum number: 3]
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.
Explain how increasing the temperature affects the rate of a reaction.
Refer to particle collision theory in your answer.
An explanation that links the following three points:
- rate of reaction increases
- mean kinetic energy of particles increases
- more successful collisions per second / per unit time / more frequent successful collisions
Allow:
- reaction is faster / speeds up
- particles move faster
- more frequent collisions having energy >= activation energy
Ignore:
- vibrate more / faster
All question bank results loaded