Which compound is a component of baking powder?

1. Analyze the question The question asks which compound is a component of baking powder. Baking powder is used to make dough or cake batter rise.

2. Explain the concept Baking powder is a mixture of:

• Sodium hydrogencarbonate (sodium bicarbonate), NaHCO₃, which is the base
• A solid acid, such as tartaric acid or cream of tartar (potassium hydrogen tartrate)
• A filler such as starch, which keeps the mixture dry

When water is added and the mixture is heated, the acid reacts with NaHCO₃ and releases carbon dioxide gas. The gas gets trapped in the dough and makes it rise, so the cake is light and fluffy.

NaHCO₃ also decomposes on heating:

2NaHCO₃ → Na₂CO₃ + H₂O + CO₂

3. Check the options

• A. Na₂CO₃ is washing soda (or soda ash). It is too alkaline for baking and is not the baking powder component.
• B. Na₂SO₄ is sodium sulfate. It gives off no CO₂, so it cannot make dough rise.
• C. KH₂CO₃ is not a real compound. The correct formula for potassium hydrogencarbonate is KHCO₃, and H₂CO₃ cannot form a stable salt in this way.
• D. NaHCO₃ is sodium hydrogencarbonate, the active ingredient that releases CO₂. ✔
• E. NaHSO₄ is sodium hydrogensulfate. It is acidic and releases no CO₂.

4. Answer The correct option is D. NaHCO₃.

5. Tip Remember: baking soda = NaHCO₃, washing soda = Na₂CO₃. If a question mentions rising dough or cake, look for the compound that gives off CO₂, which means a carbonate or hydrogencarbonate. Among the options, only NaHCO₃ is the right one.