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.

Answer 1

K2CrO4

Step-by-step explanation:

To find the empirical formula, we need to divide each element by its atomic mass. The atomic masses of potassium, chromium and oxygen are 39.0983, 51.9961 and 15.999 respectively. We make the divisions as follows:

K = 1.04/39.0983 = 0.027

Cr = 0.70/51.9961 = 0.013

O = 0.86/15.999 = 0.054

We now divide by the smallest which is the number of moles of the Chromium

K = 0.027/0.013 = 2

Cr = 0.013/0.013 = 1

K = 0.054/0.013 = 4 approximately

The empirical formula is thus:

K2CrO4