During discharge of a lead storage cell, the density of sulphuric acid in the cell:

increases

No worries! We‘ve got your back. Try BYJU‘S free classes today!

decreases

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

remains unchanged

No worries! We‘ve got your back. Try BYJU‘S free classes today!

initially increases but decreases subsequently

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B decreases
Reaction for discharge of lead storage cell is,
$P b + {S O}_{4}^{2 -} \to {P b S O}_{4} + 2 e^{-} {P b O}_{2} + {4 H}^{+} + {S O}_{4}^{2 -} + {2 e}^{-} \to {P b S O}_{4} + {2 H}_{2} O$ .
The acid reacts with the positive electrode to to release electrons. In this process the $H_{2} {S O}_{4}$ is consumed and residual water is left behind(or evaporated). So, density of sulphuric acid decreases.
So, correct answer is option B.

Suggest Corrections

Similar questions

Q. During discharge of a lead storage cell the density of sulphuric acid in the cell :

Q. Write cell reactions in lead storage battery during discharge.

Assertion: The density of

H_{2} S O_{4}

decreases in lead storage cell during discharging.

Reason: Calomel electrode is a reference electrode and it is better than hydrogen electrode.

Q. During the discharge of a lead storage battery, the density of sulphuric acid fell from

1.294

1.139 g m l^{- 1}

. Sulphuric acid of density

1.294 g m l^{- 1}

is 39% by weight and that of density

1.139 g m l^{- 1}

is 20% by weight. The battery holds 3.5 L of the acid and the volume remained practically constant during the discharge. Find the number of ampere-hours for which the battery must has been used.

The charging and discharging reactions are as follows:

$P b + S O_{4}^{2 -} \to P b S O_{4} + 2 e^{-}$ (charging)

$P b O_{2} + 4 H^{\oplus} + S O_{4}^{2 -} + 2 e^{-} \to P b S O_{4} + 2 H_{2} O$ (discharging)

During the discharge of a lead storage battery, the density of sulphuric acid fell from $1.294$ to $1.139$ gm $L^{- 1}$ . Sulphuric acid of density $1.294$ gm $L^{- 1}$ is $39$ % by weight and that of density 1.139 gm $L^{- 1}$ is $20$ % by weight. The battery holds $3.5$ litres of acid and the column practically remained constant during the discharge.

Calculate the number of ampere-hours for which the battery must have been used. The charging and discharging reactions are :

$P b + S O {_{4}}^{2 -} \to P b S O_{4} + 2 e^{-}$ (charging)

$P b O_{2} + 4 H^{+} + S O {_{4}}^{2 -} + 2 e^{-} \to P b S O_{4} + 2 H_{2} O$ (discharging)

Join BYJU'S Learning Program