NECO Chemistry Past Questions & CBT Practice

In the electrolysis of dilute tetraoxosulphate (VI) acid using platinum electrodes, the products obtained at the anode are cathode respectively are

1. A.hydrogen, oxygen
2. B.Hydrogen, tetraoxosulphate (VI) ion
3. C.oxygen, hydrogen✓ Correct
4. D.sulphur, hydrogen
5. E.sulphur, oxygen

The electrode potential in volts of 2H$^+$(aq) / H$_2$(q) system is

1. A.-2.87
2. B.-2.71
3. C.0.8
4. D.1.68
5. E.$ 0 $✓ Correct

A substance is said to be hygroscopic when it

1. A.absorbs atmospheric moisture and then goes into solution
2. B.absorbs atmospheric moisture but does not go into solution✓ Correct
3. C.changes colour
4. D.is not affected by atmospheric moisture
5. E.losses its water of crystallization

All the following belong to the same family EXCEPT

1. A.glycerol✓ Correct
2. B.nylon
3. C.perspex polyethene
4. D.polyethene
5. E.polystyrene

$ ^{235}_{92}U + ^1_0n → ^{145}_{56}Ba + ^{88}_{36}Kr + 3^1_0n + Energy $ The equation above represent a/an

1. A.alpha particle emission
2. B.endothermic reaction
3. C.nuclear fission✓ Correct
4. D.nuclear fusion
5. E.thermal dissociation

The action of zinc on an acid produces

1. A.chlorine
2. B.hydrogen✓ Correct
3. C.nitrogen
4. D.sulphur
5. E.water vapour.