Acids, bases and Kw

Question 1

What are bronsted-lowry acids?

Answer 1

Proton donors

Question 2

What are bronsted-lowry bases?

Answer 2

Proton acceptors

Question 3

What does BAAD stand for?

Answer 3

Base
Acceptor
Acid
Donor

Question 4

What do strong acids do in water?

Answer 4

Completely dissociate

Question 5

What do weak acids do in water?

Answer 5

Partly dissociate

Question 6

What is an example of a strong acid dissociating?

Answer 6

HCl -> H+ + Cl-

Question 7

What is an example of a weak acid dissociating?

Answer 7

CH3COOH CH3COO- + H+

Question 8

What do strong bases do in water?

Answer 8

Almost completely ionise

Question 9

What do weak bases do in water?

Answer 9

Partially ionise

Question 10

What is an example of a weak base ionising?

Answer 10

NH3 + H2O NH4+ + OH-

Question 11

What is an example of a strong base ionising?

Answer 11

NaOH Na+ + OH-

Question 12

Where does the equilibrium lie with strong acids and bases in water?

Answer 12

Far right

Question 13

Where does the equilibrium lie with weak acids and bases in water?

Answer 13

Far left

Question 14

Where does an acid put its protons?

Answer 14

Donates them to a base

Question 15

What is the equation for the ionic product of water?

Answer 15

Kw = [H+][OH-]

Question 16

What is the equation for the ionic product of pure water?

Answer 16

Kw = [H+]²

Question 17

Why is the equation for the ionic product of pure water different to the ionic product of water?

Answer 17

In pure water, there is always one H+ ion for every OH- ion

Question 18

Why doesn’t the expression for Kw include the concentration of water?

Answer 18

The concentration of H2O is so high compared to the concentration of [H+] and [OH-] and therefore it is effectively constant and doesn’t need to be included in the expression

Question 19

Why does the value of Kw increase with temperature increasing?

Answer 19

Dissociation is endothermic so therefore the equilibrium moves to the right hand side to absorb heat