Chemical Equilibrium

Question 1

When is a

Chemical reaction in equilibirum

Answer 1

When the compostion of reactants remains constant indefinitely

Question 2

WHat does

Value of equilibrium constant K indicate

Answer 2

Position of equilibirum

Question 3

Value of pure solids and liquids in equilibria

Answer 3

1

They are seen as constant

Question 4

Equilibirum constant K is dependent on

Answer 4

Reaction temperature ONLY.
It is independent of Concentration and pressure

Question 5

K in

Endothermic & Exothermic reactions

Answer 5

Temperature increase in endothermic reacrion increases K and yield of product.
Temperature increase in **exothermic **decreases K and yield of product

Question 6

Does a

Catalyst affect K

Answer 6

NO!

Question 7

Ionisation of water

Answer 7

2H2O(l)>H3O+(aq) +OH-(aq)

Question 8

Amphoteric

Answer 8

Can act as an acid and a base

Question 9

Dissosciation Constant for ionisation of water

Answer 9

Kw
Kw=[H3O+][OH-]

Known as the ionic product

IT VARIES WITH TEMPERATURE !!

Question 10

Kw at 25 degrees celcius

Answer 10

1 x 10-14

Question 11

What are [H3O+] and [OH-] in water and aqueous solutions with a pH of 7

Answer 11

Both are 10-7 mol l-1 at 25 degrees

Question 12

The bronsted lowry definition of acids and bases

Answer 12

An acid is a proton donor and a base is a proton acceptor

Question 13

For every ..

Answer 13

Acid there is a conjugate base, formed by the loss of a proton
Base there is a conjugate acid, formed by the gain of a proton

Question 14

Strong acids and bases

And examples

Answer 14

Completely dissociate into ions in aqueous solutions

Hydrochloric acid, sulpuric acid, nitiric acid

Metal hydroxides

Question 15

Weak acids and bases

And examples

Answer 15

Only partially dissociate into ions in aqueous solutions

Ethanoic acid, carbonic, sulfouros acid

Ammonia and amines