# How many grams in 3.75 mol of NaBr?

Feb 20, 2016

$\text{386 g}$

#### Explanation:

You can find how many grams would be equivalent to $3.75$ of sodium bromide, $\text{NaBr}$, by using the mass of one mole of this ionic compound.

As you know, the mass of one mole of a compound is expressed by that compound's molar mass. Sodium bromide has a molar mass ${\text{102.9 g mol}}^{- 1}$, which means that one mole of sodium bromide has a mass of $\text{102.9 g}$.

You can thus use the molar mass of a compound to convert between its mass and the number of moles equivalent to that mass. In your case, you will have

3.75 color(red)(cancel(color(black)("moles NaBr"))) * overbrace("102.9 g"/(1color(red)(cancel(color(black)("mole NaBr")))))^(color(purple)("molar mass")) = "385.875 g"

You need to round this off to three sig figs, the number of sig figs you have for the number of moles of sodium bromide

${m}_{N a B r} = \textcolor{g r e e n}{\text{386 g}}$