Question

Barium and nitrogen form two binary compounds containing 90.745% and 93.634% barium, respectively. Determine the empirical formulas of these two compounds.

Answer 1

Answer:

BaN, Ba₃N₂

Explanation:

In order to determine the empirical formula of a compound, we have to follow a series of steps.

Step 1: Determine the percent composition

Step 2: Divide each percentage by the atomic mass of each element

Step 3: Divide all numbers by the smallest one

Step 4: If necessary, multiply by a number so the coefficients are whole

Compound 1

Step 1

Ba: 90.745%

N: 100% - 90.745% = 9.255%

Step 2

Ba: 90.745/137.33 = 0.66078

N: 9.255/14.01 = 0.6606

Step 3

Ba: 0.66078/0.6606 ≈ 1

N: 0.6606/0.6606 = 1

The empirical formula is BaN.

Compound 2

Step 1

Ba: 93.634%

N: 100% - 93.634% = 6.366%

Step 2

Ba: 93.634/137.33 = 0.68182

N: 6.366/14.01 = 0.4544

Step 3

Ba: 0.68182/0.4544 = 1.5

N: 0.4544/0.4544 = 1

Step 4

Ba: 1.5 × 2 = 3

N: 1 × 2 = 2

The empirical formula is Ba₃N₂.