Question

$Na{ HCO }_{ 3 }$ on heating gives:
(A) ${ Na }_{ 2 }{ CO }_{ 3 }$, ${ H }_{ 2 }$, $O_{ 2 }$
(B) ${ Na }_{ 2 }{ CO }_{ 3 }$, ${ H }_{ 2 }$, $CO_{ 2 }$
(C) ${ Na{ CO }_{ 3 } }$, ${ H }_{ 2 }O$, $CO_{ 2 }$
(D) ${ Na }_{ 2 }{ CO }_{ 3 }$, ${ H }_{ 2 }O$, $CO_{ 2 }$

Answer 1

Hint: Sodium bicarbonate is an inorganic compound. Since it is an ionic salt, it is highly soluble in water since water has a high dielectric constant. It easily undergoes decomposition at temperatures above 50^oC.

Complete step by step solution:
Sodium hydrogen carbonate is an inorganic compound widely used in the food, pharmaceutical industries and as a household chemical. The deposits of this salt are known as nahcolite.
It is mass produced using synthetic methods. Out of all the methods, the Solvay process is the most widely used in which the sodium chloride, ammonia and carbon dioxide are used to produce sodium carbonate, which is further reacted with carbon dioxide and water in order to produce sodium bicarbonate.
Given below are the reactions for the preparation of sodium bicarbonate:
$ { NaCl+N{ H }_{ 3 }+{ CO }_{ 2 }+{ H }_{ 2 }O\longrightarrow { Na }_{ 2 }C{ O }_{ 3 }+{ NH }_{ 4 }Cl }$
$ { N{ a }_{ 2 }{ CO }_{ 3 }+{ CO }_{ 2 }+{ H }_{ 2 }O\longrightarrow 2NaHC{ O }_{ 3 } }$
It is an odourless, white crystalline solid and has a slightly alkaline taste. When a chemical substance decomposes it breaks down to form two or more separate compounds. Since most inorganic chemical compounds are highly stable we have to put in a lot of energy in order to break their chemical bonds. This energy can be supplied as heat, radiation, electricity or light. Sodium bicarbonate decomposes at temperatures above 50^oC and produces sodium carbonate along with water and carbon dioxide. It is this evolved carbon dioxide gas that makes baked goods rise. Therefore we use this reaction in our own kitchen in order to prepare a variety of dishes. The higher the temperature, the faster will be the decomposition reaction. Sodium bicarbonate has a high solubility in water.
Given below is the decomposition reaction for sodium bicarbonate:
$ { 2N{ a }H{ CO }_{ 3 }(s)\xrightarrow { \triangle } N{ a }_{ 2 }C{ O }_{ 3 }(s) }+{ H }_{ 2 }O(g)+{ CO }_{ 2 }(g)$
It is also known as baking soda and is sold as the main component of baking powder. It is also used as an additive in flours and other foods and beverages. But there are certain aspects that we need to be wary of while handling baking soda since it can cause serious eye damage.
Therefore the correct answer is (d) ${ Na }_{ 2 }{ CO }_{ 3 }$, ${ H }_{ 2 }O$, $CO_{ 2 }$.

Note: The appearance of the baking soda does not change as the temperature is raised. Since both; the sodium bicarbonate and sodium carbonate are white powders.