Rate Of Reaction (2)

Question 1

Describe the effect of changing the temperature on the rate of a chemical reaction

Answer 1

Low - particles move slowly so the particles will collide with each other less often and with less energy,so fewer collisions will be successful.
High - particles move faster so they will collide with each other more often and with greater energy, so many more collisions will be successful

Question 2

Describe the effect of changing the concentration on the rate of a chemical reaction

Answer 2

Low - the particles are spread out. The particles will collide with each other less often, resulting in fewer successful collisions
High - the particles are close together. The particles will collide with each other more often, resulting in many more successful collisions

Question 3

Describe the effects of changing the pressure on the rate of a chemical reaction of gases

Answer 3

Low - particles are spread out. The particles will collide with each other less often resulting in fewer successful collisions.
High - the particles are crowded more closely together. The particles collide more often, resulting in many more success collisions.

Question 4

What does the rate of reaction depend on?

Answer 4

• Collision frequency of reacting particles

- Energy transferred during the collision

Question 5

Explain using reacting particle model why changes in temperature change the rate of reaction in terms of successful collisions between particles

Answer 5

Increasing temperature causes an increase in the kinetic energy of the particles. The faster the particles move, the greater the chance of them colliding, so the number of collisions per second increases. The more collisions there are between particles, the faster the reaction. Energetic collisions = more successful collisions

Question 6

Explain using the reacting particle model why changes in concentration change the rate of reaction in terms of successful collisions between particles

Answer 6

Increasing concentration increases the number of particles in the same space, i.e. the particles are much more crowded together

Question 7

Explain using the reacting particle model why changes in pressure change the rate of reaction in terms of successful collisions between particles

Answer 7

When you increase the pressure the particles are more crowded together and this increases the frequency of collisions between the particles. The more crowded the particles are the greater the chance of them colliding together which increases the number of collisions per second.

Question 8

When do chemical reactions take place?

Answer 8

When particles collide