Question

1. what is the difference between baking soda and baking powder? why are they considered chemical leaveners? how do we test each to make sure they are still reactive?

Explanation:

• Difference: Baking soda ($\ce{NaHCO3}$) is a single compound. Baking powder is a mixture of baking soda, a dry acid (e.g., cream of tartar - $\ce{KHC4H4O6}$), and a starch (to prevent premature reactions).
• Chemical Leaveners: Both produce $\ce{CO2}$ gas through chemical reactions. Baking soda needs an acidic ingredient (e.g., yogurt, lemon juice) in the recipe to react: $\ce{NaHCO3 + H+ \to Na+ + H2O + CO2\uparrow}$. Baking powder has its own acid, so it can react without an external acid addition.
• Testing Reactivity:
• Baking Soda: Add a few drops of vinegar (acetic acid - $\ce{CH3COOH}$). If it fizzes (produces $\ce{CO2}$), it is reactive: $\ce{NaHCO3 + CH3COOH\to CH3COONa + H2O + CO2\uparrow}$.
• Baking Powder: Add warm water. If it bubbles (produces $\ce{CO2}$), it is reactive. The warm water activates the reaction between the baking soda and the acid in the baking powder: $\ce{NaHCO3 + H+ (from acid in baking powder)\to Na+ + H2O + CO2\uparrow}$.

Answer:

• Difference: Baking soda is $\ce{NaHCO3}$ (single compound), baking powder is a mixture of $\ce{NaHCO3}$, an acid, and starch.
• Chemical Leaveners: Produce $\ce{CO2}$ via chemical reactions (baking soda with external acid, baking powder with internal acid).
• Testing Reactivity: Baking soda - add vinegar (fizzing means reactive); Baking powder - add warm water (bubbling means reactive).