Electrolysis of Aqueous solutions

Question 1

In aqueous solution, what ions will be present.

Answer 1

H^+ and OH^- from the water. H20 (l) ⇌ H^+ (aq) + OH^- ( aq)

At the cathode, H+ ions and metals ions are present. Hydrogen produced if metal ions form an elemental metal that is more reactive than hydrogen. If metal ions form an elemental metal that is less reactive than hydrogen, a solid layer of pure metal will be produced instead.

At the anode, If OH^- and halide ions ( group 7) are present, molecules of the halide ion ( bromine ) will be formed. If no halide ions are present, OH^- will be discharged and oxygen will be formed.

Question 2

PRACTICAL 1-3

Answer 2

1) a SOLUTION OF COPPER SULFATE ( CUS04) contains 4 different ions : Cu^2+, SO4^2-, H^+ and OH^-

2) Copper metal is less reactive than hydrogen. So at the cathode, copper metal is produced and coats the electrode.

Cu^2+ + 2e^- —> Cu

Question 3

PRACTICAL 4-5

Answer 3

4)There aren’t any halide ions present, so at the anode oxygen and water is produced, the oxygen can be seen as bubbles.

5) big 4 OH^- —> O2 + big 2 H2O + big 4 e^-

Question 4

PRACTICAL 6-7

Answer 4

6) Set up the electrolysis experiment in lab. Once the experiment is done. You can test any gaseous products produced.

7) Chlorine bleaches damp litmus paper turning it white
Hydrogen makes a “squeaky pop” with a lighted splint.
Oxygen will relight a glowing splint

Question 5

Half equations

Answer 5

Negative - 2 = 1
postive = 1 - 2 or 2 2