# If the "empirical formula" is CH, and the molecular mass is 26*g*mol^-1, what is the "molecular formula"?

May 9, 2017

The molecular formula is always a whole number of the empirical formula...........

#### Explanation:

............and of course the multiple may be one.

And thus $\text{molecular formula"="n"xx"empirical formula}$

And so the given molecular mass is $26 \cdot g \cdot m o {l}^{-} 1$.

And so $26 \cdot g \cdot m o {l}^{-} 1 = n \times \left(12.0 \cdot g + \times 1 \cdot g\right)$

Clearly, $n = 2$, and the molecular formula is ${C}_{2} {H}_{2}$, which is good because of course we know that $\text{acetylene} = H - C \equiv C - H$, i.e. two degrees of unsaturation.