Question

3. State your observations when equal volumes of
hydrogen and chlorine are exposed to :
4. Briefly describe your observations when
(a) diffused sunlight
(b) direct sunlight
hydrogen gas is passed over heated copper
oxide.
5. State four uses of hydrogen gas.
6. State two tests of hydrogen gas.
7. Why is the mixture of hydrogen and helium used
in weather observation balloons, instead of pure
hydrogen?
8. By giving examples explain the following terms:
(a) Oxidation
(b) Reduction.​

Answer 1

Answer:

3. diffused sunlight

4.If hydrogen gas is passed over heated copper oxide (CuO), the black coating on the surface turns brown as the reverse reaction takes place and copper is obtained. ... The hydrogen is gaining oxygen and is being oxidised.In other words, one reactant gets oxidised while the other gets reduced

5. Hydrogen: uses

a) commercial fixation of nitrogen from the air in the Haber ammonia process.

b) hydrogenation of fats and oils.

c) methanol production, in hydrodealkylation, hydrocracking, and hydrodesulphurization.

d) rocket fuel.

e) welding.

f) production of hydrochloric acid.

g) reduction of metallic ores.

6. Burning splint test

A splint is lit and held near the opening of the tube, then the stopper is removed to expose the splint to the gas. If the gas is flammable, the mixture ignites. This test is most commonly used to identify hydrogen, which extinguishes with a distinctive 'squeaky pop' sound

7. why is the mixture of hydrogen and helium used in weather observation, balloons, istead of pure hydrogen. Hydrogen is a very explosive gas. ... So helium is used along with hydrogen to dilute its effects. It is used instead of other noble gases because it is the second lightest element after hydrogen

8. Oxidation is gain of oxygen.

2H2 +O 2

→2H 2 O

The hydrogen is oxidized and the oxygen is reduced.

N 2 +O 2

→2NO

This formation of nitric oxide oxidizes the nitrogen and reduces the oxygen.

Reduction is the loss of oxygen from a substance. For example, copper oxide can be reduced to form copper if it is reacted with hydrogen:

CuO+H 2

→Cu+H 2 O

Zinc oxide can be reduced to zinc metal if heated with carbon.

ZnO+C→Zn+CO

hope it's help you buddy