Determine the empirical formula for a compound with 68.4% Cr and 31.6% O. Show your work in the space below.

Cr2O3

Explanation:

To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:

68.4% Cr = 68.4g of Chromium

31.6% O = 31.6g of Oxygen

Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.

Cr = 68.4/52 = 1.315 mol

O = 31.6/16 = 1.975 mol

- Next, we divide each mole value by the smallest value (1.315mol)

Cr = 1.315/1.315 = 1

O = 1.975/1.315 = 1.50

The ratio or Cr to O is 1:1.5

We multiply this ratio by 2 to get the whole number ratio as follows:

2 × 1: 2 × 1.5

2:3

Hence, the empirical formula of Cr and oxygen is Cr2O3.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

i don,t know so just answer mine