A2 PH - DEFINING ACIDS ]

Question 1

The Brnnsted-Lowry description of acidity

Answer 1

An acid is a molecule which donates a proton and a base accept the base

Question 2

Monoprotic Acid

Answer 2

donates one proton

Question 3

Diprotic acid

Answer 3

donates 2 protons

Question 4

Water can act as

Answer 4

a base and a acid

Question 5

H3O +

Answer 5

H30 + is called the oxon ium ion, but the names hydronium ion and

hydroxonium ion are also used.

Question 6

Why is H+ Called a proton

Answer 6

it has lost a electron, therefore this means that it only has a proton in the nucleus as no neutrons are present

since there is no electrons they can never give electrons only accept electrons

Question 7

Water is slightly ionised:

Answer 7

This means it existed as this in equilibrium
H20(l) .- H+(aq) + oH-(aq)

It can also be written in the form

H20(l) + H20(1) …- H 30•(aq} + OH-(aq)

Question 8

Kw

Answer 8

The equilibrium constant, Kw, is called the dissociation constant or ionization constant of water.

Question 9

In pure water what is The Kw constant

Answer 9

1.00x10-7 M.

Question 10

More kw

Answer 10

Kw is called the ionic product of water and at 298k it is equal to
1.0 x 10-14 mol 2 dm-6 • Each H20 that dissociates (splits up) gives rise
to one H+ and one oH- so. in pure water, a t 298 K :

Question 11

why is water always at a constant

Answer 11

Because equilibrium lies to the left a lot there is a small value of ions so water is at a constant

Question 12

at 298k water

Answer 12

it is 1 x 10-14

what is the Ph value since dissociation is one to one
h+ is 1 x10-7
so Ph is 7 in pure water - our interpretation of neutral

Question 13

at 373k water

Answer 13

it has a Ph of 6.14
it appears acidic
the charges balance out so it is neutral Ph
the neutral point has changed.

Question 14

What does a proton exist as

Answer 14

the proton does not exist in itself but rather it interacts with water to form H30+