C8

Question 1

Acid + Metal =?

Answer 1

salt + hydrogen

Question 2

Acid +metal oxide =?

Answer 2

Salt + water

Question 3

Acid + Carbonate =?

Answer 3

Salt + Water + Carbon dioxide

Question 4

Difference between strong and weak acids ?

Answer 4

Strong acids completely dissociate into ions

Weak acids partially dissociate into ions

Question 5

a pure, dry sample of solid lead carbonate can be obtained from
sodium carbonate solution and lead nitrate solution

Answer 5

React lead carbonate with sodium carbonate solution
Filter the Precipitate
wash the solid residue with distilled water
leave to dry

Question 6

How do we prepare copper sulphate

6

Answer 6

Reaction is : CuO+H2SO4=CuSo4+H2O

Measure some dilute sulphuric acid into a conical flask
Warm the acid in a water bath
add copper oxide until the copper oxide in in excess in the flask
filter the mixture and transfer the filtrate into an evaporating basin
gently heat the copper sulphate in an evaporating basin
stop heating when crystals start to form
Put solution in a watch glass and wait till all the water is evaporated

Question 7

How do we investigate ph. using calcium hydroxide and hydrochloric acid

Answer 7

add dilute hydrochloric acid to a beaker
Add a few drops of universal indicator. Compare the initial colour of the solution to a pH
colour chart and record the pH. Alternatively, a pH probe can be used.
Add calcium hydroxide or calcium oxide (one level spatula at a time) to the beaker, stirring
and recording the pH between additions.
Stop adding calcium hydroxide/calcium oxide when the pH remains constant.