Question #1e60c

1 Answer
Nov 9, 2016

1.66 * 10^(26)

Explanation:

It's worth remembering that you can go from moles to molecules by using a single conversion factor.

More specifically, you can convert the number of moles of a molecular substance to number of molecules by using Avogadro's constant

color(purple)(bar(ul(|color(white)(a/a)color(black)("1 mole" = 6.022 * 10^(23)"molecules")color(white)(a/a)|))) -> Avogadro's constant

You are given moles and asked to find the number of molecules, so set up the conversion factor as

"no. of molecules"/"1 mole" = (6.022 * 10^(23)"molecules CO"_2)/"1 mole CO"_2

Plug in your value to find

2.76 * 10^2 color(red)(cancel(color(black)("moles CO"_2))) * (6.022 * 10^(23)"molecules CO"_2)/(1color(red)(cancel(color(black)("mole CO"_2))))

=color(green)(bar(ul(|color(white)(a/a)color(black)(1.66 * 10^(26)"molecules CO"_2)color(white)(a/a)|)))

The answer is rounded to three sig figs.