pH and salts 1.5

Question 1

what is Kw

Answer 1

ionic product

Question 2

Kw calculation

Answer 2

[H3O+] [OH-]

Question 3

Kw at room temperature

Answer 3

1.01 x 10^-14

Question 4

what are [H3O+] and [OH-] in neutral solutions

Answer 4

1 x 10^-7

Question 5

why are [H3O+] and [OH-] in neutral solutions low

Answer 5

because equilibrium lies far to the left

Question 6

why can water act as both an acid and a base

Answer 6

because of its ions

Question 7

amphoteric

Answer 7

when water act as both an acid and a base

Question 8

pH + pOH =

Answer 8

14

Question 9

how are salts made

Answer 9

by neutralisation reactions

Question 10

salt’s properties

Answer 10

can be soluble (evaporation) or insoluble (filtration) and are strong electrolytes (completely ionised in solution)

Question 11

what acid base reaction are soaps

Answer 11

weak acids and strong base

Question 12

buffers

Answer 12

a solution that stays approximately the same pH when small amounts of acid, base or water are added

Question 13

acid buffers

Answer 13

made from a weak acid and one of its salts made with a strong base

Question 14

adding a base to an acid buffer

Answer 14

the weak acid can provide H+ ions to replace the ones removed by the base

Question 15

adding an acid to an acid buffer

Answer 15

the salt provides the conjugate base which can absorb the excess H+ ions

Question 16

basic buffers

Answer 16

made from a weak base and one of its salts (conjugate acid)

Question 17

adding an acid to a basic buffer

Answer 17

weak base removed excess H+ ions

Question 18

adding a base to a basic buffer

Answer 18

conjugate acid supplies H+ ions

Question 19

indicators

Answer 19

determines the end point, are weak acids

Question 20

what reactions are indicators not needed

Answer 20

weak acid-weak base titrations as pH won’t change quickly