How many moles of sucrose, C12H22O11, are found in a sugar cube with a mass 4 grams?
So the first thing I noticed about this problem is that it's asking for
moles and it's giving me grams.
So that's a big clue that I'm going to be using my molar mass.
So the first thing I want to do is actually calculate that molar mass.
And I'm going to do that based on the information given here about the formula.
I notice that I have carbon.
And there are 12 of those, each which has a 12.00 gram per mole for its molar mass.
Hydrogen.
There are 22.
Times its molar mass of 1.008 grams per mole.
And oxygen.
We have 11 times 16.00 grams per mole.
So I'm going to be able to take and
add up those values to find the molar mass of sugar.
And what I find is that the molar mass
is 342.2 grams per mole for sucrose.
Now that gives me the molar mass.
It doesn't tell me anything about the number of moles that are in
this mass of just 4 grams.
So now I need to take my 4 grams of my sugar.
And I'm going to use the molar mass,
only this time I'm going to put 342.2 grams per mole.
So I'm putting the grams on the bottom because what I need to happen is for
grams to cancel with grams.
So now when I do the calculation what I end up with is a unit of moles for
my answer.
So I could take 4 divided by 342.2 and
get a molar amount which
0.0117 moles of sucrose, or C12H22O11.