1. Baking powder is a 1:1 molar mixture of cream of tartar (KHC4H4O6) and baking soda (NaHCO3). A recipe calls for two teaspoons (a total of 8.0 grams) of cream of tartar. How much baking soda must be added for both materials to react completely?

3.57 g.

Explanation:

The ratio of cream of tartar (KHC₄H₄O₆) to baking soda (NaHCO₃) in the baking powder is 1:1. We need to calculate the number of moles of (8.0 g) of cream of tartar (KHC₄H₄O₆) using the relation: n = mass / molar mass,

mass of cream of tartar (KHC₄H₄O₆) = 8.0 g.

molar mass of cream of tartar (KHC₄H₄O₆) = 188.1772 g/mol.

∴ n of cream of tartar (KHC₄H₄O₆) = mass / molar mass = (8.0 g) / (188.1772 g/mol) = 0.0425 mol.

Since the mole ratio of the two components is 1:1, the no. of moles of baking soda (NaHCO₃) should be added is 0.0425 mol. The quantity of baking soda (NaHCO₃) can be calculated using the relation:

mass = n x molar mass = (0.0425 mol) (84.007 g/mol) = 3.57 g.