How do you calculate the mass of one mole of such hydrogen giving your answer to atoms four decimal places? (The Avogadro constant, L= 6.0225 xx 10^23 mol^-1)?

Jan 7, 2017

$\text{Mass of 1 mole of hydrogen atoms}$ $=$ ${\text{Mass of 1 hydrogen atom"xx"N}}_{A}$, where ${\text{N}}_{A} = L = 6.0225 \times {10}^{23} \cdot m o {l}^{-} 1$.

Explanation:

$\text{Mass of 1 hydrogen atom}$ $=$ $1.6727 \times {10}^{- 27} \cdot \text{kg}$ (from this site).

And thus, $\text{mass of 1 mole of hydrogen atoms}$ $=$

$1.6727 \times {10}^{- 27} \cdot \text{kg"xx6.0225xx10^23*mol^-1xx10^(3)*"g} \cdot k {g}^{-} 1$

$= 1.007 \cdot {\text{g"*"mol}}^{-} 1$

Clearly, you would not be expected to know these masses. You would be expected to be able to do such a calculation if provided with the masses of the nucleon, and with $\text{Avogadro's number}$.

What is the mass of one mole of hydrogen molecules?