# How many moles of H_2 are in 4.48*10^-4 g of H_2?

Jul 5, 2016

Approx. $2 \times {10}^{-} 4 \cdot m o l$

#### Explanation:

$\text{Moles of dihydrogen}$ $=$ $\text{Mass"/"Molar mass}$

$=$ $\frac{4.48 \times {10}^{-} 4 \cdot g}{2 \times 1.00794 \cdot g \cdot m o {l}^{-} 1}$ $=$ ??mol

Note that this is consistent dimensionally. We wanted an answer in moles, and the equation duly gives us an answer in moles.

In terms of hydrogen atoms, how many atoms of hydrogen does this molar quantity represent? Why?