Calculate the number of unit cells in 0.79 g metal if product of density and volume of unit cell is $1.58 \times 10^{-22} \mathrm{~g}$.

Identify secondary amine from following.

Which from following polymers is biodegradable?

The standard emf for cell, ${ }^{\ominus} \mathrm{Cd}_{(\mathrm{s})}\left|{ }^{+2} \mathrm{Cd}(1 \mathrm{M}) \| \stackrel{+2}{\mathrm{Cu}}(1 \mathrm{M})\right| \mathrm{Cu}_{(\mathrm{s})}{ }^{\oplus}$ is 0.74 V .

If concentration of $\mathrm{Cd}_{(\mathrm{aq})}^{+2}$ and $\mathrm{Cu}_{(\mathrm{aq})}^{+2}$ decreases by 10 times at 298 K . Calculate emf of cell.