What is the mass of 2.94 times 10^24 molecules of decane C_10H_22?

Apr 5, 2017

Well, $6.022 \times {10}^{23}$ individual decane molecules have a mass of $142.3 \cdot g$
$6.022 \times {10}^{23}$ individual items of stuff specifies a $\text{mole of stuff}$. The $\text{mole}$ relates the (sub) micro world of atoms and molecules to the macro world of grams and litres.
${\text{mass"=(2.94xx10^24*"molecules")/(6.022xx10^23*"molecules"*"mol"^-1)xx142.3*g*"mol}}^{-} 1 \cong 700 \cdot g$