pls help in this qs

Dear student

i) Substance C is least soluble in water at 200^oC.

ii)Substance D is most soluble in water at 200^oC

iii)Mass of B required to make a solution in 100g water is 20g [ from the table]
So, for 50g the amount will be
$$\begin{gathered} \frac{20}{100}\times 50 \\ =10g \end{gathered}$$

iv)At 200^oC, the amount of E is formed =32g( from table]
So, the amount of E that will separate out is 100- 32 = 68g

v) Generally the solubility of salt increases with increase in temperature.
But all solutions do not show the same effect of temperature. For example all the given salts show a gradual increase in solubility with increase in temperature, except the salt C.

Regards