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chemistry igcse acapprinted 31 · PDF 31
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31
In the above setup of a fuel cell, the oxygen is provided by the air that is entering and the fuel
entering is the hydrogen. Water is the only waste product of the fuel cell. The movement of
hydrogen, oxygen and electrons is shown in the above diagram.
Advantages and Disadvantages:
Advantages
Disadvantages
Process is renewable since the hydrogen can
be obtained from the water.
Hydrogen is expensive and difficult to store
as it is flammable and can easily explode.
More energy is released per kilogram as
compared to petrol and diesel.
Hydrogen produced by combustion of
fossil fuels releases carbon dioxide.
Hydrogen produced by the electrolysis of
water requires a very large amount of
electricity.
It does not cause any pollution because
water is the only product.
Fuel cells are badly affected by low
temperatures which reduce their efficiency.
It does not contribute to noise pollution.
It is very expensive.
Since there are no moving parts, no power
is lost in transmission.
Number of hydrogen filling stations across
the countries is very low.
P2:
Q1. Concentrated aqueous sodium chloride and dilute sulfuric acid are both electrolysed using
inert electrodes. Which row identifies the product at the cathode in each electrolysis?
Aqueous Sodium Chloride
Dilute Sulfuric Acid
A
B
Hydrogen
Hydrogen
Oxygen
Hydrogen