Hello!
Firstly, we need to determine the atomic formula of carbon monoxide.
When breaking down the name, we know that there is only one carbon atom since we normally do not add the prefix mono- (one), in the front of the first element. Secondly, there is one oxygen atom since mono = one, and oxide is oxygen. Carbon monoxide is written as: CO.
Now, to find the number of molecules, we will need to use a conversion factor, and also we must know Avogadro's number: <u>6.02 x 10^23 molecules</u>.
To set up the conversion factor, we must change the units from "moles CO" to "molecules CO". To do that, we will begin with the given number, "0.75 moles CO", and multiply that by "6.02 x 10^23 molecules CO over 1 mol CO".
0.75 moles CO x (6.02 x 10^23 molecules CO / 1 mol CO) = 4.52 x 10^23 molecules CO
Therefore, there are about 4.52 x 10^23 molecules CO.
