How many hydrogen atoms in a 23.7*g MASS of methane?

Oct 5, 2016

$\frac{23.7 \cdot g}{16.04 \cdot g \cdot m o {l}^{-} 1} \times {\text{4 hydrogen atoms mol}}^{-} 1 \times {N}_{A}$ $=$
??"how many hydrogen atoms."
${N}_{A} = \text{Avogadro's number,}$ $6.022 \times {10}^{23}$
We work the molar quantity to get an answer in moles of methane. Because for each mole of methane there four moles of hydrogen atoms, we multiply this number by four to get an answer in moles of hydrogen. Because for each mole there $\text{Avogadro's number}$ of particles, we (finally!) multiply this last number by ${N}_{A}$ to get the number of hydrogen atoms.