chemical changes

Question 1

what are the 2 ways of measuring pH

Answer 1

an indicator or pH probe connected to a pH metre

Question 2

which of the ways of measuring pH is more accurate and why

Answer 2

pH metre as it does not rely on humans guessing shades and gives an accurate testament

Question 3

what is an acid

Answer 3

any substance that forms an aqueous solution with a pH below 7

Question 4

what is a base

Answer 4

any substance with a pH above 7

Question 5

what is an alkali

Answer 5

a base that dissolves in water to form a solution with a pH greater than 7

Question 6

what happens if you mix an acid and alkali

Answer 6

a neutralisation reaction, forming salt and water

Question 7

what will always be made when a metal oxide/ hydroxide reacts with an acid

Answer 7

salt and water

Question 8

what will always be made when a metal carbonate reacts with an acid

Answer 8

salt, water and carbon dioxide

Question 9

what do we have to react together in order to make an soluble salt

Answer 9

react an acid with an insoluble base (like a metal oxide/hydroxide/carbonate)