Chapter 13, Problem 6STP

Interpretation Introduction

Interpretation:

The empirical formula is to be calculated using percentage composition.

Concept introduction:

The empirical formula is the formula which gives the simplest whole number ratio of the atoms present in the formula.

Answer to Problem 6STP

A

Explanation of Solution

To calculate empirical formula of a compound, percentage to the atomic mass ratio is calculated and converted into simple whole number ratio.

Element	Percentage	Atomic mass	%/mass	Simple ratio	Whole no. ratio
Li	28.98	6.9	4.2	1	1
O	66.81	15.9	4.20	1	1
H	4.21	1	4.21	1	1

The simplest whole number ratio is:

$Li:O:H=1:1:1$

Therefore empirical formula is $LiOH$

Conclusion

The calculations show correct empirical formula is $LiOH$. Therefore option A is correct.