Question

1. Sodium bicarbonate, baking soda, is routinely used in cooking.

a. If you add 2.0 teaspoons of baking soda to flour, how many molecules of sodium bicarbonate are contained in the mixture? 1 tsp = 4.93 mL. Density of sodium bicarbonate = 2.2 g/cm3.

b. Is the resultant flour and baking soda mixture heterogeneous or homogeneous? Explain

Answer 1

density of sodium bicarbonate = 2.2 g/cm3.

density = Mass/Volume

Mass = Density x Volume = 2..2 x 4.93 (for each table spoon) = 10.846 gram /tsp

you used 2 table spoons,

So total weight of Sodium bicarbonate = 2 x 10.846 = 21.692 grams

The molecular mass is the atomic weight in grams for a mole, or approximately (6.022 x 10²³)

Therefore, no. of moles of Sodium bicarbonate = weight / molecualr weight = 21.692/84 = 0.25824mole

per mole = 6.022 x 10²³

per 0.25824 mole = 0.25824 x 6.022 x 10²³ molecules = 1.555 x 10²³ molecules

2. resultant mixture is Homogenous. Since there is no way to distinguish between the flour and the baking powder. The two components of the mixture are uniformly mixed.