Question

Baking soda (nahco3) is an active ingredient in some antacids. determine the percent composition of oxygen in baking soda.

Answer 1

Assuming the question is asking for percent composition by mass,

The molar mass of sodium bicarbonate is:

22.990 + 1.008 + 12.011 + 3*15.999 = 84.006 g/mol

The molar mass of 3 oxygen atoms is:

3*15.999 = 47.997 g/mol

The percentage composition by mass is:

47.997/84.006 * 100% = 57.1% (3 s.f.)