Question

Complete and balance the following equation:

(c) ${\mathrm{CaSO}}_4+\mathrm{NaOH}\to \mathrm{\_\_\_\_\_\_\_\_\_\_}$

Answer 1

Reaction of sodium hydroxide and calcium salts

Sodium hydroxide $\left(\mathrm{NaOH}\right)$ reacts with calcium salts to form a white precipitate of calcium hydroxide $\left(\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right)$. For calcium chloride salt, the reaction is as follows

${\mathrm{CaCl}}_2\left(\mathrm{aq}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)\to 2\mathrm{NaCl}\left(\mathrm{aq}\right)+\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\downarrow \left(\mathrm{s}\right)$

However, this reaction is not possible with calcium sulfate $\left({\mathrm{CaSO}}_4\right)$.

Calcium sulfate

• Calcium sulfate is insoluble in water due to high lattice energy.
• It is an insoluble white solid that precipitates out of the solution.

Reaction summary:

• When Calcium sulfate $\left({\mathrm{CaSO}}_4\right)$ reacts with sodium hydroxide solution $\left(\mathrm{NaOH}\right)$, there will be no reaction.
• This reaction is not feasible as Calcium sulfate will be insoluble in sodium hydroxide.

This chemical reaction will not take place.

${\mathrm{CaSO}}_4\left(\mathrm{aq}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)\to \underline{\mathrm{No}\mathrm{reaction}}$