Question

How do you convert `5.3 * 10^25` molecules of `CO_2` to moles?

Answer 1

There are 88 moles of `CO_2` in `5.3xx10^(25)` molecules of `CO_2`

Explanation:

In order to go from molecules of `CO_2` to moles of `CO_2`, we have to use the following relationship:

I usually set up dimensional analysis questions like this:

Quantity sought = Quantity given x conversion factor

• Quantity sought `rarr` mol `CO_2`
• Quantity given `rarr` `5.3xx10^(25)` molecules
• Conversion factor `rarr` `(1mol)/(6.02xx10^(23))`

Now we just plug the values into the format I have above (make sure your units cancel out as you are going through this process, that's how you know if you are doing the calculations correctly or not):

moles `CO_2` = `5.3xx10^(25)cancel "molecules" xx` `(1mol)/(6.02xx10^(23)cancel"molecules"`

moles `CO_2` = 88 mol