1. Determine the empirical formula of a compound

containing 59.0% Na and 41.0% O by mass.

(a) NaO

(b) Na2O

(c) NaO2

(d) Na2O3

(e) none of these

NaO

Explanation:

Empirical formula:

It is the simplest formula gives the ratio of atoms of different elements in small whole number.

Given dа ta:

Percentage of sodium = 59.0%

Percentage of oxygen = 41%

Empirical formula = ?

Solution:

Number of gram atoms of Na = 59.0 / 23 = 2.6

Number of gram atoms of O = 41 / 16 = 2.6

Atomic ratio:

Na : O

2.6/2.6 : 2.6/2.6

1 : 1

Na : O = 1:1

Empirical formula is NaO.