Question #fc45c

Aug 21, 2017

$\text{0.133 moles}$

Explanation:

The idea here is that you need to use the molar mass of sucrose to calculate the number of moles present in your sample.

You know that sucrose has a molar mass of ${\text{342.3 g mol}}^{- 1}$, which means that $1$ mole of sucrose has a mass of $\text{342.3 g}$.

You want to go from grams to moles, so set up the molar mass of the substance as a conversion factor that has moles in the numerator and grams in the denominator.

You should end up with

$45.4 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{g"))) * "1 mole sucrose"/(342.3 color(red)(cancel(color(black)("g")))) = color(darkgreen)(ul(color(black)("0.133 moles sucrose}}}}$

The answer is rounded to three sig figs.