Question

Determine the following to four significant figures:

(a) the percent composition of hydrazoic acid, HN₃
(b) the percent composition of TNT, C₆H₂(CH₃)(NO₂)₃
(c) the percent of SO₄ 2-in Al₂(SO₄)₃

Answer 1

To determine the percent composition of a compound, find the molar mass of each element, divide by the molar mass of the compound, and multiply by 100. Round to four significant figures. Example calculation provided.

Step-by-step explanation:

To determine the percent composition of a compound, first find the molar mass of each element in the compound. Then, divide the molar mass of each element by the molar mass of the entire compound and multiply by 100 to get the percent composition.

For example, for (a) hydrazoic acid, HN3, the molar mass of H is 1 g/mol and the molar mass of N is 14 g/mol. The molar mass of the compound is 1 + 14*3 = 43 g/mol. The percent composition of H is (1/43)*100 = 2.33% and the percent composition of N is (14/43)*100 = 32.56%.

Follow the same steps for the other compounds in the question and round the percent compositions to four significant figures.