Question #d14a0

1 Answer
Sep 21, 2017

Answer:

#"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.