The element which is not common between the compounds called baking soda and soda ash is ?

Question

Accepted Answer

Baking soda and soda ash are two different chemical compounds with distinct compositions. Baking soda is chemically known as sodium bicarbonate, with the formula NaHCO₃. Soda ash, on the other hand, is known as sodium carbonate, with the formula Na₂CO₃.

1. **Explanation for Option 1 (Hydrogen):**
   - Baking soda (NaHCO₃) contains hydrogen as part of its chemical structure. The presence of hydrogen is evident in the bicarbonate (HCO₃⁻) ion.
   - Soda ash (Na₂CO₃), however, does not contain hydrogen in its chemical structure. It consists of sodium (Na), carbon (C), and oxygen (O) only.
   - Therefore, hydrogen is the element that is not common between baking soda and soda ash, making Option 1 the correct answer.

2. **Explanation for why other options are incorrect:**
   - **Option 2 (Oxygen):** Both baking soda and soda ash contain oxygen. In baking soda, oxygen is part of the bicarbonate ion (HCO₃⁻), and in soda ash, it is part of the carbonate ion (CO₃²⁻). Thus, oxygen is common to both compounds.
   - **Option 3 (Sodium):** Sodium is present in both compounds. Baking soda is sodium bicarbonate (NaHCO₃), and soda ash is sodium carbonate (Na₂CO₃). Therefore, sodium is common to both.
   - **Option 4 (Carbon):** Carbon is also present in both compounds. It is part of the bicarbonate ion in baking soda and the carbonate ion in soda ash. Hence, carbon is common to both compounds.

In conclusion, hydrogen is the only element that is not shared between baking soda and soda ash, which justifies why Option 1 is the correct answer.