Can someone please help me? I'm so confused with Moles!

Hi! I have a test tomorrow and I still don't really understand some of these questions. :(

For example: How many moles of sulfuric acid in 15.24g of the acid?

I really don't know how to even start doing that.
Thank you so much~

Okay, think of moles as a basic universal unit.
You can use this basic unit to find other values, like weight (in grams).
You go from moles to grams and from grams to moles by using the molar mass. The molar mass is the total atomic mass of the compound or chemical your using.

So, in your example we're dealing with sulfuric acid, which is H2SO4. We need to find the molar mass of sulfuric acid to convert it from grams to moles.

That's 2 hydrogens, 1 sulfur and 4 oxygens. From the Periodic Table, you can see that the atomic mass of hydrogen is 1.008, the atomic mass of sulfur is 32.07 and the atomic mass of oxygen is 15.99. Now, just set it up like a math problem!

2(1.008) + 1(32.07) + 4(15.99) = The molar mass of H2SO4, which is 98.046 grams / mole
(The units for molar mass is grams per mole)

So to go from grams to moles, you DIVIDE the grams by the molar mass. (To go from moles to grams you MULTIPLY by the molar mass)

It says we have 15.24 grams of sulfuric acid, so DIVIDE that by the molar mass to get moles.

(15.24 grams) / (98.046 grams/mol) = 0.1554 moles of sulfuric acid
(If you do the math you see that the grams cancel each other out and your just left with moles as your units!)

Hope that helped :)

Actually I don't have moles. So I can't help you. lol