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

Which of the following statements is correct?

In a $Cu-Zn$ cell,.....

Which of the following solutions cannot be used in a salt bridge?

Give the cell reaction and symbolic representation of the galvanic cell obtained by $E^o_{Ni^{2+}|Ni} = -0.23 \ V$ and $E^o_{Ag^{+}|Ag} = 0.80 \ V$.

The position of some metals in the electrochemical series in decreasing electropositive character is given as $Mg > Al > Zn > Cu > Ag$. What will happen if a copper spoon is used to stir a solution of aluminium nitrate?