Question

Carbonates which are soluble in water are:
A. Sodium Carbonate
B. Potassium Carbonate
C. Both A and B
D. None of these

Answer 1

Alkali carbonates are soluble in water that are the carbonates of alkali metals. Potassium and sodium are referred to as alkali metals so carbonates of sodium and potassium are soluble in water. Potassium carbonate and sodium carbonate are inorganic compounds having molecular formula as ${K_2}C{O_3}$ and $N{a_2}C{O_3}$ respectively.

Complete step-by-step answer: Potassium carbonate is a white salt which is soluble in water and it is deliquescent. Frequently it appears as wet solid. It is the primary component of potash.
Uses of Potassium carbonate:
1. For soap, glass and china production.
2. As a mild drying agent.
3. As a buffering agent in production of wine.
4. As a fire suppressant in extinguishing deep-fat fryers.
5. As an acidity regulator in Swedish snus.
Sodium carbonate is a white compound and soluble in water and yields moderately alkaline solutions in water. Sodium carbonate is produced in large quantities from sodium chloride and lime stone by Solvay process.
Uses of Sodium carbonate:
1. Glass manufacture
2. Water softening
3. Food additive and cooking
4. Inexpensive, weak bases
5. Precursor to other compounds.
Both sodium carbonate and potassium carbonate are soluble in water.

So, option C is correct.

Note: Potassium carbonate is not suitable for acidic compounds as a mild drying agent, but it can be used in drying an organic phase if one has a small amount of acidic impurity. It may also be used to dry some ketones, alcohols, and amines before distillation.
Sodium carbonate decahydrate ( $N{a_2}C{O_3}.10{H_2}O$ ), is washing soda, it is the most common hydrate of sodium carbonate containing 10 molecules of water of crystallization. Soda ash is dissolved in water and crystallized to get washing soda.