What is the number of ethyl alcohol molecules in a 22.26*g mass?

Feb 6, 2016

Approx. half a mole. Therefore approx. $\frac{1}{2}$ Avogadro's number.

Explanation:

Moles of ethanol $=$ $\frac{22.26 \cdot g}{46.07 \cdot g \cdot m o {l}^{-} 1}$. This molar quantity represents a fraction of Avogadro's number.

In $1$ $m o l$ of stuff there are ${N}_{A}$ individual items of that stuff, where ${N}_{A}$ $=$ $6.022 \times {10}^{23}$.

So the answer $=$ $\frac{22.26 \cdot \cancel{g}}{46.07 \cdot \cancel{g} \cdot \cancel{m o {l}^{-} 1}}$ $\times$ $6.022 \times {10}^{23} \cdot \cancel{m o {l}^{-} 1}$ $=$ ??

We get a dimensionless number, as is required for a number.