Question

The acid used in lead storage cell is:

• A. Phosphoric acid
• B. Nitric acid
• C. Sulphuric acid
• D. Hydrochloric acid

Answer 1

Answer: (C)

Sulphuric acid

Lead storage battery or lead-acid battery, is one type of rechargeable battery and one of the common energy storage devices in which sulfuric acid is used.

During discharge, both the positive and negative electrodes become lead(II) sulfate ($PbS{O}_4$). The electrolyte loses much of its sulfuric acid which is in dissolved state and becomes water. The discharge process is carried out by the conduction of electrons from the negative electrode back into the cell at the positive electrode in the external circuit.

Negative plate reaction: $Pb\left(s\right)+HS{O}_4^{-}\left(aq\right)\to PbS{O}_4\left(s\right)+H^{+}\left(aq\right)+2e^{-}$

Positive plate reaction: $Pb{O}_2\left(s\right)+HS{O}_4-\left(aq\right)+3H^{+}\left(aq\right)+2e^{-}\to PbS{O}_4\left(s\right)+2H_{2}O\left(l\right)$

Hence option C is correct