The empirical formula of a group of compounds is CHCl.Lindane,a powerful insecticide,is a member of this group.The molar mass of lindane is 290.8 g/mol.How many atoms of carbon does a molecule of lindane contain?
A)2
B)3
C)4
D)6
E)8

Question

Quizplus · Accepted Answer

The empirical formula of CHCl shows that there is one carbon atom in each molecule of the compound. The molar mass of lindane (290.8 g/mol) can be used to calculate the molecular formula.

Molecular formula mass = (Empirical formula mass) x n
where n is the factor by which the empirical formula must be multiplied to get the molecular formula

Empirical formula mass = (1 x 12.01 g/mol) + (1 x 1.01 g/mol) + (1 x 35.45 g/mol) = 48.47 g/mol

n = Molecular formula mass / Empirical formula mass = 290.8 g/mol / 48.47 g/mol = 6

Multiplying the empirical formula by 6 gives C6H6Cl6, which is the molecular formula for lindane. This formula shows that there are 6 carbon atoms in each molecule of lindane. Therefore, the answer is D (6).

The Empirical Formula of a Group of Compounds Is CHCl