Write down the formula of Copper(II) sulphate pentahydrate.

A. ${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}$

B. ${\mathrm{CuSO}}_4.{\left({\mathrm{H}}_2\mathrm{O}\right)}_5$

C. $5{\mathrm{CuSO}}_4.{\mathrm{H}}_2\mathrm{O}$

"Enter your correct answer as A, B or C."

Write down the name of the compound represented by the formula: ${\mathrm{NaNO}}_3$

(Sodium nitrite/ Sodium nitrate)

 $$\begin{gathered} \mathrm{A}: \mathrm{Chromium}\left(\mathrm{III}\right) \mathrm{sulphate} \\ \mathrm{B}: \mathrm{Chromium}\left(\mathrm{II}\right) \mathrm{sulphate} \\ \mathrm{C}: \mathrm{Chromium}\left(\mathrm{I}\right) \mathrm{sulphate} \end{gathered}$$

(Enter your correct answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$)