A 170.00g sample of an unidentified compound contains 29.84g sodium,67.49g chromium, and 72.67g oxygen. find the emperical formula.

Answer : The empirical formula for the given compound is

Explanation : Given,

Mass of Na = 29.84 g

Mass of Cr = 67.49 g

Mass of O = 72.67 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Na =

Moles of Cr =

Moles of O =

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 1.297 moles.

For Na =

For Cr =

For O =

The ratio of Na : Cr : O = 1 : 1 : 3.5

To make the ratio in a whole number we are multiplying the ratio by 2, we get:

The ratio of Na : Cr : O = 2 : 2 : 7

Step 3: Taking the mole ratio as their subscripts.

Empirical formula for the given compound is

Hence, the empirical formula for the given compound is

"the periodic table is arranged in order of atomic number."