Question

Question #47af6

Answer 1

`"190 g"`

Explanation:

Your goal here is to convert the number of moles of sodium fluoride to grams.

To do that, you can use the molar mass of the compound, which tells you the mass of exactly `1` mole of sodium fluoride.

Sodium fluoride has a molar mass of `"41.998 g mol"^(-1)`, which implies that `1` mole of sodium fluoride has a mass of `"41.998 g"`.

You can thus say that your sample will have a mass of

`4.5 color(red)(cancel(color(black)("moles NaF"))) * overbrace("41.998 g"/(1color(red)(cancel(color(black)("mole NaF")))))^(color(blue)("the molar mass of NaF")) = color(darkgreen)(ul(color(black)("190 g")))`

The answer is rounded to two sig figs, the number of sig figs you have for the number of moles present in your sample.