**When baking powder is heated or mixed with water, it undergoes a chemical reaction that releases carbon dioxide gas. This reaction is essential for creating the light and fluffy texture in baked goods. Let's delve into the details of what happens during this process.**

**1. Composition of Baking Powder:**
Baking powder is a leavening agent commonly used in baking. It is a mixture of three key ingredients:
- Baking Soda (sodium bicarbonate): A base that reacts with acids to produce carbon dioxide gas.
- Acidic salts (such as cream of tartar): These acids react with baking soda to initiate the carbon dioxide release.
- Starch: It acts as a stabilizer and prevents the reaction from occurring prematurely.

**2. Reaction Mechanism:**
When baking powder is heated or mixed with water, the following chemical reaction takes place:
- The acidic salts in baking powder (e.g., cream of tartar) react with water, dissociating into their respective ions.
- The bicarbonate ions from baking soda react with the hydrogen ions from the acidic salts, resulting in the formation of carbon dioxide gas.
- This reaction is generally represented as:
NaHCO3 + H+ → Na+ + CO2 + H2O

**3. Leavening Effect:**
The release of carbon dioxide gas is responsible for the leavening effect in baked goods. Here's how it works:
- As the carbon dioxide gas is produced, it forms bubbles in the dough or batter.
- These bubbles get trapped in the gluten matrix or other structural components of the mixture.
- When the baked goods are exposed to heat, the gas bubbles expand due to the increased temperature, causing the dough or batter to rise and become light and airy.
- The network of gluten and starch sets during baking, trapping the gas and providing the desired texture.

**4. Importance of Baking Powder:**
Baking powder plays a crucial role in baking for several reasons:
- It acts as a leavening agent, making the baked goods rise and creating a desirable texture.
- It helps in tenderizing the final product by interfering with the formation of gluten strands.
- It contributes to the browning and flavor development in the baked goods.

In conclusion, when baking powder is heated or mixed with water, a chemical reaction occurs that releases carbon dioxide gas. This gas creates bubbles, which get trapped in the dough or batter, causing it to rise and create a light and fluffy texture. Baking powder is an essential ingredient in baking, providing leavening, tenderness, and flavor to the final product.