Experiment No. 32

Testing Baking Powders for Phosphoric Acid

Dissolve ½ gm. of baking powder in 5 cc. of H2O and 3 cc. HNO3. Filter and add 3 cc. ammonium molybdate. Heat gently. A yellow precipitate indicates phosphoric acid.

1. How do you test a baking powder for phosphoric acid? 2. What is the yellow precipitate obtained in this test?