Question

An alkanol contains 37.5 carbon

12.5 hydrogen
a: obtain its empirical formular
b; if its molecular mass is 32g obtain its molecular formula​

Answer 1

Empirical formula is CH₄

Molecular formula = C₂H₈

Step-by-step explanation:

Mass of carbon = 37.5 g

Mass of hydrogen = 12.5 g

Molecular weight = 32 g/mol

Molecular formula = ?

Empirical formula = ?

Solution:

Number of gram atoms of C = 37.5 g /12g/mol = 3.125

Number of gram atoms of H = 12.5 g / 1.008 g/mol= 12.4

Atomic ratio:

C : H

3.125/3.125 : 12.4 /3.125

1 : 4

C : H : = 1 : 4

Empirical formula is CH₄

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

n = 32 / 16

n = 2

Molecular formula = n (empirical formula)

Molecular formula = 2 ( CH₄)

Molecular formula = C₂H₈