Question

Question #77d78

Answer 1

`5.53`

Explanation:

The idea here is that in order to ahve `1` mole of carbon dioxide, you need to have `6.022 * 10^(23)` molecules of carbon dioxide.

So if your sample of carbon dioxide contains `6.022 * 10^(23)` molecules of carbon dioxide, you can say that it contains `1` mole of carbon dioxide, as stated by Avogadro's constant.

In your case, the sampel contains `3.33 * 10^(24)` molecules of carbon dioxide, so right from the start, you know that the sample contains more than `1` mole.

To find the number of moles present in the sample, use Avogadro's constant as conversion factor. Set it up with `1` mole on top and `6.022 * 10^(23)` molecules on the bottom to get

`3.33 * 10^(24) color(red)(cancel(color(black)("molecules CO"_2))) * overbrace("1 mole CO"_2/(6.022 * 10^(23)color(red)(cancel(color(black)("molecules CO"_2)))))^(color(blue)("Avogadro's constant")) = color(darkgreen)(ul(color(black)("5.53 moles CO"_2)))`

The answer is rounded to three sig figs, the number of sig figs you have for the number of molecules of carbon dioxide present in the sample.