Kinetics

Question 1

Catalysts

Answer 1

A catalyst is a substance that increases the rate of a chemical reaction without being changed in chemical composition or amount.

Catalysts work by providing an alternative reaction route of lower activation energy.

Different catalysts are used for different reactions.

Question 2

Activation energy

Answer 2

Reactions can only occur when collisions take place between particles having sufficient energy is the activation energy.

Question 3

explain why most collision do not lead to reaction

Answer 3

1. For a reaction to occur the particles must collide in the right direction.
2. They must also have a minimum amount of kinetic energy
   ( Collision Theory )

Question 4

What must be maintained for a reaction to take place

Answer 4

the reaction must follow the collision theory

Question 5

use the Maxwell–Boltzmann distribution to explain why a small temperature increase can lead to a large increase in rate.

Answer 5

The particles move around more at higher temperatures. they collide more often, hence the reason why reactions happen faster at higher temperatures.
The combination of more collision and more energetic collision means that a small increase in temperature leads to a large increase in rate.

Question 6

Definition: Rate of Reaction

Answer 6

The change of concentrations / the amount of a reactant or product per unit of time.

Question 7

The qualitative effect of changes in concentration on collision frequency.

Answer 7

Increasing concentration will increase the rate of reaction. Particles are close together and collide more often. There are more frequent collisions and a higher chance of reactions.

Question 8

Explain how a change in pressure influences the rate of a reaction.

Answer 8

Increasing the pressure will increase the rate of reaction. Practices are close together and collide more often. There are more frequent collisions and a higher chance of reactions.

Question 9

The effect of changing the concentration of acid on the rate of a reaction of calcium carbonate and hydrochloric acid by a continuous monitoring method.

Answer 9

This reaction can be used to investigate the effect of varying the concentration of the acid while keeping the temperature constant
When a gas is released in a reaction you can either try to measure the volume of gas given off or the mass change in the reaction flask

Question 10

Explain how a catalyst increases the rate of a reaction involving a gas.

Answer 10

The gases first form weak bonds with the metal atoms of the catalyst- this process is called adsorption. This hold the gases in just the right for them to react together. The gases then react on the surface.

Question 11

Define the term Electronegativity

Answer 11

Power of an atom to attract a pair of electron towards it self in a covalent bond