What is the density of a solution of sulphuric acid used as an electrolyte in lead accumulators (in $g \ mL^{-1}$)?

While charging the lead storage battery,

Which of the following changes occurs during the discharging of a lead accumulator?

In the electrochemical cell $H_{2(g)}, 1 \ atm \ | \ H^+_{(aq)}, 1 \ M \ || \ Cu^{2+}_{(aq)}, 1 \ M \ | \ Cu_{(s)}$,which of the following statements is true?

Which of the following reactions is possible at the anode?

In the cell $Zn | Zn^{2+} || Cu^{2+} | Cu$,the negative electrode is