Chemical changes

Question 1

What does the pH scale go to from

Answer 1

0-14

Question 2

State different ways to check the pH of a solution

Answer 2

methyl orange- red acid , orange neutral and alkali
phenophthalein-colourless acid /neutral and pink alkali
universal indicator -pH chart compare colour
litmus paper-red acid,blue alkali,purple neutral

Question 3

what is a neutralisation reaction?

Answer 3

when an acid and base react together to form a salt and water concentration of hydrogen ions = to concen of hydroxide ions

Question 4

what difference between alkali and base?

Answer 4

base that dissolve in water = alkali

base usually metal oxides/hydroxides

Question 5

What do acids produce and bases produce?

explain difference between weak and strong acid

Answer 5

H + ions and OH- ions
strong-large proportion of a molecules dissociate to release H+ ions .pH 0-2 ionise almost completely in water
weak-small proportion of molecules dissociate…
pH 2-6 don t fully ionise in solution

Question 6

Explain the diff between acid strength and concentration of an acid/alkali

Answer 6

strength-tells you proportion of a molecules that can ionise in water
con-how much acid is in a certain volume of water
more grams of acid per dm 3 =high concen
vice versa low concen/dilute

Question 7

How concentration and pH are linked

Answer 7

H+ ions increase by factor of 10 ,pH - by 1.

if increases by factor of 100 (10 x 10) pH - by 2 so on