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### E23 part b

Posted: Fri Oct 12, 2018 1:06 am
The question E23 part says "Calculate the amount (in moles) of (a) Cu^2 ions in 3g of CuBr2 (b) SO3 molecules in 7.00x10^2mg of SO3" For part b I'm a bit confused. I got the right answer but thought we were suppose to convert 0.00874 moles into molecules since it said "SO3 molecules".

### Re: E23 part b

Posted: Fri Oct 12, 2018 1:42 am
No, even though it says SO3 molecules, it still wants you to find the number of moles. The question wants you to treat the molecule as a whole, and find the number of moles of the molecule. In part a you find the number of moles of an ion, and likewise in part b you find the number of moles of a molecule. moles can be used to describe an amount of anything.

### Re: E23 part b

Posted: Fri Oct 12, 2018 11:26 am
Unless it specifically asks you for the number of molecules, then you would need to take the moles and convert it to molecules by multiplying the number of moles with Avogadro's number. Otherwise, the problem just says find the number of moles so you're good where you're at

### Re: E23 part b

Posted: Fri Oct 12, 2018 11:27 am
For part b, it is asking for the amount in moles of SO3 molecules, so the answer would be in moles. Moles can be used to describe the amount of atoms, molecules, ions, electrons, other particles, or specified groups of such particles.

### Re: E23 part b

Posted: Fri Oct 12, 2018 1:28 pm
I also got confused here.

But as in the beginning it says you are looking the amount of moles and even though it says molecules you're looking for the amount of moles in that molecule they presented.