Question

3. What's the empirical formula of a molecule containing 18.7% lithium, 16.3% carbon, and 65.0% oxygen?

Answer 1

Answer:

Empirical formula is  Li₂CO₃.

Explanation:

Percentage of oxygen= 65.0%

Percentage of lithium = 18.7%

Percentage of carbon= 16.3%

Empirical formula = ?

Solution:

Number of gram atoms of C = 16.3/12 = 1.4

Number of gram atoms of Li = 18.7/6.94 = 2.7

Number of gram atoms of O = 65.0/ 16 = 4.1

Atomic ratio:

Li              :            C          :    O

2.7/1.4      :       1.4/1.4         :   4.1/1.4

     2          :            1           :     3  

Li : C : O = 2 : 1 : 3

Empirical formula is  Li₂CO₃.