Concept:Dilute sulfuric acid is used in the electrolysis of water to increase the conductivity of water without interfering with the products of electrolysis.
Explanation:Pure water is a poor conductor of electricity because it contains very few free ions.
To make electrolysis possible, a small amount of a strong acid, dilute sulfuric acid, is added to the water.
The dilute
H2SO4 provides enough ions to carry electric current through the water.
At the cathode, hydrogen gas is produced, and at the anode, oxygen gas is produced.
Using dilute
H2SO4 gives only hydrogen and oxygen as the products of the decomposition of water.
Dilute
HNO3 and dilute
HCl may also conduct, but they can lead to undesirable reactions at the electrodes.
Acetic acid,
CH3COOH, is a weak acid and is not typically used for this purpose.
Therefore, the acid used in the electrolysis of water is dilute sulfuric acid.
Answer:C.
H2SO4