Question

Analysis of a compound indicates that it contians 1.04 g k, 0.70 g cr, and 0.86 g o. find its empirical formula. 1. k2cro3 2. kcro4 3. k2cro4 4. kcro3

Answer 1

Empirical formula of a chemical compound is the simplest positive integer ratio of atoms in the compound.
The first step is getting the number of moles of each.
Potassium- 1.04/39 = 0.0267
Chromium- 0.7 /52 = 0.0135
Oxygen- 0.86/16 = 0.05375
Then we divide each with the smallest number,
0.0267/0.0135= 1.98
0.0135/0.0135=1
0.05375/0.0135= 3.98
Therefore the ratio is 2:1:4
Hence the empirical formula is K2CrO4