Question

Question #d14a0

Answer 1

`"45 lbs"`

Explanation:

You know that the chocolate bars contain `22.0%` by mass pecans. This means that you get `"22.0 kg"` of pecans for every `"100 kg"` of chocolate bars.

Your first step here will be to use the given percent concentration by mass as a conversion factor to calculate how many kilograms of chocolate bars will contain `"4.5 kg"` of pecans.

`4.5 color(red)(cancel(color(black)("kg pecans"))) * "100 kg chocolate bars"/(22.0color(red)(cancel(color(black)("kg pecans")))) = 225/11color(white)(.)"kg chocolate bars"`

Now, in order to convert this to pounds, you need to use the fact that

`"1 kg " ~~ " 2.2046 lbs"`

You will end up with

`225/11 color(red)(cancel(color(black)("kg"))) * "2.2046 lbs"/(1color(red)(cancel(color(black)("kg")))) = color(darkgreen)(ul(color(black)("45 lbs")))`

The answer is rounded to two sig figs, the number of sig figs you have for the mass of pecans.