Question

A compound with the empirical formula ch2 has a molar mass of 98 g/mol what is the molecular formula for this compound ?

Answer 1

C7H14

Step-by-step explanation:

The empirical formula indicates that the number of hydrogen atoms is twice the number of carbon atoms in this compound. Therefore, possible molecular formulas include C2H4, C3H6, etc.

The molar mass (98 g/mol) is a multiple of the formula mass of CH2 (14 g/mol). Determine how many times 14 goes into 98. This is the number of CH2 units in the molecule. which is 7

CH2(7)= answer

Answer 2

Approximate molecular masses:
Molecular mass of C = 12
Molecular mass of H = 1

Let n = moles required for CH₂.
Then
nCH₂ = 98
n(12 + 2*1) = 98
14n = 98
n = 7

Answer: The molecular formula is 7CH₂