Question

A 170.0 g sample of an unidentified compound contains 29.84 g sodium, 67.49

g chromium, and 72.67 g oxygen. What is the compound's empirical formula?

Answer 1

The empirical formula : Na₂Cr₂O₇

Further explanation

Given

170 g sample contains :

29.84 g sodium, 67.49 g chromium, and 72.67 g oxygen

Required

The compound's empirical formula

Solution

mol ratio of elements :

Na : 29.84 : 23 g/mol = 1.297

Cr : 67.49 : 51,9961 g/mol = 1.297

O : 72.67 : 16 g/mol = 4.54

Divide by 1.297

Na : Cr : O = 1 : 1 : 3.5 = 2 : 2 : 7