Equilibrium & Reversible Reactions

Question 1

What will all reversible reactions reach

Answer 1

Equilibrium

Question 2

What can happen in a reversible reaction

Answer 2

The products (C+D) can react to form the reactants (A+B)

Question 3

What is a closed system

Answer 3

No reactants or products can escape and nothing can get in

Question 4

When equilibrium lies to the right…

Answer 4

.. the concentration of products is greater than that of the reactants

Question 5

When equilibrium lies to the left….

Answer 5

The concentration of reactants is greater than that that of the products

Question 6

What conditions affect the position of equilibrium

Answer 6

• the temperature
• ## the pressure (only affects equilibria involving gases)

Question 7

In reversible reactions if the reaction is endothermic in one direction what will the the direction be

Answer 7

exothermic

Question 8

What does it mean when a system is in equilibrium

Answer 8

Both the forward and reverse reactions are happening at the same rate

Question 9

What is le chateliers principle

Answer 9

The idea that if you change the conditions of a reversible reaction at equilibrium, the system will try to counteract that change

Question 10

What is le chateliers principle useful

Answer 10

It can be used to predict the effect of any changes you make to a reaction system

Question 11

How does temperature affect the position of equilibrium

Answer 11

1.if you decrease the temperature, the equilibrium will move in the exothermic direction to produce more heat
2. This means that you’ll get more products for the exothermic reaction and fewer products for the endothermic reaction
3. If you increase the temperature the equilibrium will shift to the endothermic direction to try and decrease it.
4. This mens that you’ll now get more products for the endothermic reaction and fewer products for the exothermic reaction

Question 12

How does pressure affect the position of equilibrium

Answer 12

1. Changing the pressure only affects equilibrium involving gases
2. If you increase the pressure, the equilibrium tries to reduce it by shifting to the side where there are fewer molecules
3. If you decrease the pressure, the equilibrium tries to increase it by shifting to the side where there are more molecules

Question 13

How does concentration affect the position of equilibrium

Answer 13

1. If you change the conc. of either the reactants or the products, the system will no longer be at equilibrium
2. So the system responds to bring itself back to equilibrium again
3. If you increase the concentration of the reactants the system tries to decrease it by making more products
4. If you decrease the concentration of products the system tries to increase it again by reducing the conc. Of reactants