Lab Activity 5 Baking Soda VS. Baking Powder

1. Lab Activity 5Baking Soda VS. Baking Powder IUG, Fall 2012 Dr TarekZaida

2. Background • instead of yeast, we often use either baking soda or baking powder-sometimes both. • It takes much less time to bake with them. • Batters, such as those used for pancakes and certain cakes, contain much more liquid than does the bread dough made with yeast. • These batters are so thin that slow-acting yeast cannot trap enough air to make bubbles. • That’s why we use chemicals.

3. Baking soda is sodium bicarbonate (NaHCO3) sometimes called bicarbonate of soda. • Some people use it for: 1. brushing their teeth, 2. absorbing refrigerator odors, 3. or as an antacid for ingestion! Baking soda is an alkali, when it combines with an acid, it produces carbon dioxide (bubbles).

4. NaHCO3+ CH3COOH CH3COONa + H2CO3CO2 + H2O • When baking powder is added to water or milk, the alkali and the acid react with one another to produce carbon dioxide bubbles.

5. Experiment 1 • Reagents: • Water, • Baking soda, • Lemon juice, • Orange juice

6. Procedure • Measure and record pH of each food being tested. • Add 1 teaspoon of baking soda to 100 ml water. • Add 1 teaspoon of baking soda to 100 ml lemon or orange juice. • Describe what happens

7. Experiment 2 Reagents • Water, • ½ teaspoon baking soda, • ½ teaspoon baking powder

8. Procedure • Add the baking powder to 50 ml of water. • Add the baking soda to 50 ml of water. • Describe what happens in each case

9. Experiment 3 Reagents • Orange or lemon juice • ½ teaspoon baking soda • ½ teaspoon baking powder

10. Procedure • Add the baking powder to 50 ml orange or lemon juice • Add baking soda to 50 ml orange or lemon juice • Explain what happens