At nearly 70°C, sodium bicarbonate shows the property of gradually dec

At nearly 70°C, sodium bicarbonate shows the property of gradually decomposing, which makes it usable in bakery products. The product of decomposition responsible for this use of sodium bicarbonate is

Carbon dioxide
Hydrogen
Water vapour
Oxygen
This question was previously asked in
UPSC NDA-2 – 2020
The correct answer is (A) Carbon dioxide.
Sodium bicarbonate (baking soda, NaHCO3) is used in bakery products as a leavening agent. When heated, it decomposes according to the reaction: 2NaHCO3(s) → Na2CO3(s) + H2O(g) + CO2(g). The gaseous products, water vapour and especially carbon dioxide, are trapped within the dough, causing it to expand and become light and porous. Carbon dioxide is the primary gas responsible for the leavening action.
The resulting sodium carbonate (Na2CO3) is a residual solid. While water vapour also contributes to the rise, carbon dioxide is the main leavening gas produced from this decomposition at baking temperatures. Hydrogen and oxygen are not significant products of this specific decomposition reaction.