01.
|
i |
ii |
iii |
iv |
v |
|
A |
B |
C |
C |
A |
02. PREPARATION OF OXYGEN
01. Zn (s)
+ 2HCl (aq) à ZnCl2 (aq) + H2 (g)
02. (i)
Hydrogen is used to fill a weather balloon because is lighter than air.
(ii)
Hydrogen is used to produce oxy-hydrogen flame because it is highly flammable.
03. (i) The gas observed was Hydrogen gas.
(i)
Physical
properties of hydrogen gas
·
It
is tasteless, odourless and colourless
·
It
is lighter than air
·
It
is slightly soluble in water
·
It
does not support combustion
(ii)
Chemical properties of hydrogen
·
It
combine easily with other chemical substances at high temperatures.
·
It
does not usually react with other elements at room temperature.
·
It
is highly flammable and burns with a blue flame.
·
A
mixture of hydrogen and oxygen explodes when lit.
·
It
reacts with oxides and chlorides of many metals to produce free metals.
·
It
reacts slowly with oxygen to produce water.
H2
(g) + O2 (g) à H2O (l)
·
It
is neither acidic nor basic.
(iii)
When
hydrogen gas reacts with oxygen water is formed.
Reaction:
H2
(g) + O2 (g) à H2O (l)
(iv)
When
the mixture of the gas (hydrogen gas) and oxygen lit it explodes.
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