Baking powder contains:

Options

A. `NaHCO_(3), Ca(H_(2)PO_(2))_(2)` and starch
B. `NaHCO_(3), Ca(H_(2)PO_(2))_(2)`
C. `NaHCO_(3)`, starch
D. `NaHCO_(3)`

Answer

To answer the question about what baking powder contains, we can break down the information step by step.

### Step-by-Step Solution:

1. **Identify the Main Ingredient**:
- Baking powder primarily contains sodium bicarbonate, which is chemically represented as NaHCO3. This compound is responsible for the leavening action in baking.

2. **Identify Acid Salts**:
- In addition to sodium bicarbonate, baking powder also contains one or more acid salts. A common acid salt used in baking powder is mono calcium phosphate, which has the chemical formula CaH2PO4 (often written as Ca(H2PO4)2 for clarity).

3. **Include Other Ingredients**:
- Starch is another component that is often included in baking powder. Starch helps to absorb moisture and keep the baking powder dry, ensuring it remains effective.

4. **Percentage Composition**:
- The composition of baking powder typically includes:
- Sodium bicarbonate (NaHCO3): about 30%
- Mono calcium phosphate (CaH2PO4): about 5-12%
- Starch: about 21-26%

5. **Conclusion**:
- Therefore, the correct answer to the question "Baking powder contains" is:
- Sodium bicarbonate (NaHCO3)
- Mono calcium phosphate (CaH2PO4)
- Starch

### Final Answer:
Baking powder contains NaHCO3 (sodium bicarbonate), CaH2PO4 (mono calcium phosphate), and starch.