Question

A compound of molecular mass 28 has a molecular formula CxHy. What is the value of x and y if its empirical formula is CH?

Answer 1

x = 2, y = 2

Step-by-step explanation

The empirical formula is the simplest whole number ration that defines constituent atoms in a species.

The molecular formula is always a multiple of the empirical formula.

Since the empirical formula of the compound i given to be CH, ithen its molecula formula is:

`Molecular\text{ }formula=n*(empirical\text{ }formula)`

From the periodic table, the molar masses of (H = 1.00784, C = 12.011)

Thus, the molecular formula is

`\begin{gathered} Molecular\text{ }formula=28\text{ }g\text{/}mol=n(12.011+1.00784)\text{ }g\text{/}mol \\ \\ n=(28)/(12.011+1.00784)=(28)/(13.01884)=2.150729251\approx2 \end{gathered}`

(CH)n = (CH)₂ = C₂H₂

Therefore, CxHy = C₂H₂. The value of x and y is 2 and 2 respectively.

The value of x and y if its empirical formula is CH is x = 2, y = 2