molar to percentage

[lboogy]

Hi everyone,

 

Can I just check with you, is 0.1M 10%? So to get from molar to % we just multiply by 100? Is that correct?

 

thanks in advance...and sorry forthe simplicity

[ecoli]

So a 20M solution would be 200 %? Think again.

[lboogy]

yeah...but i though 1.0 would be the maximum i.e. 100%.

 

could anyone help me please?

 

p.s. if 0.1M was 10%, then 20M would be 2000% not 200% ;-)

[John Cuthber]

To understand molarity you need to know what a mole is (and I don't mean a small burrowing mammal).

This might help

http://en.wikipedia.org/wiki/Molarity#Molarity

[lboogy]

From wikipedia:

"The mole fraction Χ, (also called molar fraction) denotes the number of moles of solute as a proportion of the total number of moles in a solution. For instance: 1 mole of solute dissolved in 9 moles of solvent has a mole fraction of 1/10 or 0.1"

 

I don't understand how this isn't 10%. I know I'm getting wrong, as you guys have told me, but my understanding from this is that the molar of a solution is a percentage the solute takes up of the whole solution. Please tell me what I'm getting wrong!

 

thanks

[Bignose]

Please don't take this as in a snarky or mean or putting you down tone. It is not what I mean. But, lboogy, did you read the wili link John posted?

 

Specifically, "Molarity (M) denotes the number of moles of a given substance per liter of solution." Nothing about mole fraction, which is a very different quantity. Molarity has units of moles/liter. Mole fraction would be moles/moles or unitless.

[ecoli]

p.s. if 0.1M was 10%, then 20M would be 2000% not 200% ;-)

 

 

haha.. oh yeah.

 

No, you can definately have more than a 1M solution. Read the provided link.

[lboogy]

Yeah, so I think I get it now, One mole of a substance contains 6.02 x (10)23 formula units.

 

thanks for your help guys.....I realise my questions must seem a bit daft, sorry.