Chemical reactions

Question 1

what is a catalyst

Answer 1

substance that increases the rate of reaction and is unchanged at the end of the reaction

Question 2

what does a catalyst decrease?

Answer 2

the activation energy

Question 3

Describe the effect on the rate of reaction of changing the concentration of solutions

Answer 3

Increasing the concentration of reactants in a solution generally leads to an increase in the rate of reaction. This is because a higher concentration of reactant molecules means that there are more molecules available to collide with each other, increasing the frequency of collisions and, therefore, the rate of reaction. This effect is known as an increase in the reaction rate due to an increase in the concentration of the reactants, or simply an increase in concentration.

Conversely, decreasing the concentration of reactants in a solution will generally lead to a decrease in the rate of reaction. This is because a lower concentration of reactant molecules means that there are fewer molecules available to collide with each other, reducing the frequency of collisions and, therefore, the rate of reaction. This effect is known as a decrease in the reaction rate due to a decrease in the concentration of the reactants, or simply a decrease in concentration.

Question 4

Describe the effect on the rate of reaction of changing the pressure of gases

Answer 4

Increasing the pressure of a gas will generally lead to an increase in the rate of reaction. This is because an increase in pressure leads to a decrease in volume, causing the gas molecules to become more densely packed and increasing the frequency of collisions between them. As a result, the rate of reaction increases. This effect is known as an increase in the reaction rate due to an increase in pressure, or simply an increase in pressure.

Conversely, decreasing the pressure of a gas will generally lead to a decrease in the rate of reaction. This is because a decrease in pressure leads to an increase in volume, causing the gas molecules to become more spread out and decreasing the frequency of collisions between them. As a result, the rate of reaction decreases. This effect is known as a decrease in the reaction rate due to a decrease in pressure, or simply a decrease in pressure.

Question 5

Describe the effect on the rate of reaction of changing the surface area of solids

Question 6

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

Question 7

Describe the effect on the rate of reaction of adding or removing a catalyst, including enzymes

Question 8

using collision theory explain n the effect on the rate of
reaction of changing the concentration of solutions

Question 9

using collision theory explain the effect on the rate of
reaction of changing the pressure of gases
(c) changing the surface area of solids
(d) changing the temperature
(e) adding or removing a catalyst, including
enzymes

Question 10

using collision theory explain the effect on the rate of
reaction of changing the surface area of solids

Question 11

using collision theory explain the effect on the rate of
reaction of changing the temperature

Question 12

using collision theory explain the effect on the rate of
reaction of adding or removing a catalyst, including
enzymes

Question 13

what does a catalyst decrease?

Answer 13

the activation energy of a reaction

Question 14

Describe practical methods for investigating the
rate of a reaction including change in mass of a
reactant or a product and the formation of a gas

Question 15

Evaluate practical methods for investigating the
rate of a reaction including change in mass of a
reactant or a product and the formation of a gas

Question 16

Define a redox reaction

Answer 16

a reaction involving simultaneous oxidation and reduction

Question 17

Define oxidation

Answer 17

as gain of oxygen

Question 18

define reduction

Answer 18

loss of oxygen

Question 19

name the differences of reduction and oxidation in terms of electrons and oxidation numbers

Answer 19

oxidation= gain of electrons and an increase of oxidation num

reduction=loss of electrons and a decrease of oxidation num

Question 20

Define an oxidising agent

Answer 20

a substance that oxidises another substance and is itself reduced

Question 21

Define a reducing agent

Answer 21

a substance that reduces another substance and is itself oxidised