Chemistry Calculation

Hi i was doin my chemistry hw and i am stuck on couple of question. Can anyone help me plz.

1) what is the concentration in mol dm3 of a solution of potassium hydroxide, KOH, containing 4.13g dm3?

2) what is the concentration in g dm3 of a solution of potassium manganete (v11) KMnO4, containing 0.0200 mol dm3?

thanks alot

Reply 1

JayEm

All you have to do is convert grams to moles for the first one. The second question is the reverse of the first.

moles=mass/Mr

Reply 2

Lrilol

greenford

1) what is the concentration in mol dm3 of a solution of potassium hydroxide, KOH, containing 4.13g dm3?

Moles = Mass / Relative Molecular Mass

2) what is the concentration in g dm3 of a solution of potassium manganete (v11) KMnO4, containing 0.0200 mol dm3?

Mass = Moles * Relative molecular mass.

Spoiler

Reply 3

itsyahg

use the formula of g dm-3 = mol dm-3 * Mr

Reply 4

Pigster

I'm fairly sure that six years later, greenford will have finished his A-level chemistry course, finished his degree and probably has a job, husband/wife and kids by now.

Your answer, though, is correct.

Reply 5

itsyahg

Original post by Pigster

well it was for anyone else stuck on that question, just like I was and I found the answer though some research, so I thought it would make others' life easier if I answered the question.