Question

Calculate the empirical formula of the compounds whose percentage composition is given below.
a. 50% calcium, 15 % carbon and 35 % nitrogen

Answer 1

Answer:

50 per calcium

15 per carbon

35 per nitrogen

= 100 PER

Answer 2

Explanation:

Given;

50% calcium;

15% carbon;

35% nitrogen.

For simplicity consider a compound weighing 100g made up from 50g of calcium, 15g of carbon and 35g of nitrogen.

Mole of calcium used = 50/40 = 5/4 (mass/molar mass)

Mole of carbon used = 15/12 = 5/4

Mole of nitrogen used = 35/14 = 5/2

Multiply the mole of respective elements with 4/5;

Thus, Mole of calcium used = 5/4 × 4/5 = 1;

Mole of carbon used = 5/4 × 4/5 = 1;

Mole of nitrogen used = 5/2 × 4/5 = 2.

Therefore, the resulting compound will have 1 atom of carbon, 1 atom of calcium and 2 atoms of nitrogen.

Thus, the empirical formula is CaCN2.

That's all.