Question

what is the molecular formula of the compound CH2 with molar mass =168g/mol?

Answer 1

first, let's find the molar mass of CH₂. 

molar mass CH₂= 12.0 + (2 x 1.01)= 14.02 g/mol

Now to determine the molecular formula, we need to find the ratio based in the molar masses. 

$\frac{168}{14.02} = 12$

The ratio is 12. so the molecular formula is 12 x CH₂ ----> C₁₂H₂₄

Answer 2

Answer: The molecular formula to the given empirical formula is $C_{12}H_{24}$

Explanation:

Empirical formula is defined as the simplest form of the chemical formula that represents the whole number of atoms of each element that are present in the compound.  Here, the empirical formula is $CH_2$

Molecular formula is defined as the chemical formula that represents the actual number of atoms of each element that are present in the compound.  

To determine the molecular formula, we first need to determine the valency which is then multiplied by each element to get the molecular formula.

The equation which is used to calculate the valency follows:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

Empirical mass = $(12+2)=14g/mol$

Molecular mass = 168 g/mol

Putting values in above equation, we get:

$n=\frac{168g/mol}{14g/mol}=12$

Now, multiplying this number to the subscripts of atoms of $CH_2$, it gives:

$C_{(1\times 12)}H_{(2\times 12)}=C_{12}H_{24}$

Hence, the molecular formula to the given empirical formula is $C_{12}H_{24}$