Author Topic: making mol solution  (Read 2231 times)

0 Members and 1 Guest are viewing this topic.

kreiselmeier

  • Guest
making mol solution
« on: June 02, 2003, 12:25:00 PM »
Hi, am I right, if I want to make  1 mol H2SO4, I add 98 (1Mol) gramm of conz. H2SO4 to 1Liter of Dest H2O ?

Sorry but my books where a bit fuzzy abhout this subject

raffike

  • Guest
No,the amount of water must be around 950 mls...
« Reply #1 on: June 02, 2003, 12:30:00 PM »
No,the amount of water must be around 950 mls or so that the final amount of solution would be 1000 mls.Then it's 1 M H2SO4 solution


gabd

  • Guest
And remember its always
« Reply #2 on: June 02, 2003, 04:16:00 PM »
acid to water. So you add you water first then your sulfuric acid. Dont drop H2O in the sulfuric, do the opposite. As for volume, you would need 1 mol in a total of 1 liter. Sulfuric has a density of around 1.86. So 1 mole is 98g / 1.86 = 52.7ml so that means 947.3 ml of water

This is a 1 molar H2SO4 solution, but remember there is 2 protons so its also a 2N solution.

kreiselmeier

  • Guest
??? there is a diffrence between M=mol and N??
« Reply #3 on: June 06, 2003, 12:39:00 PM »
First of all thank you for the help, but my books do not say anything about N so if i have to prepare a 2,5 N H2SO4 Solution, how do I proceed? I thought from the writings that somtimes the writers replace N for M or it is a typo mistake, please enlighten me...

raffike

  • Guest
N is normality,M is molarity,i think there is...
« Reply #4 on: June 06, 2003, 12:46:00 PM »
N is normality,M is molarity,i think there is a difference when it comes to acids with anions with more neutrons over than 1 like SO4-2
Not sure though... ::)


LaBTop

  • Guest
UTFSE!
« Reply #5 on: June 06, 2003, 03:32:00 PM »
normality molarity
put that in the ""and Subject / Body:""  window, you get 23 hits! LT/


calcium

  • Guest
D. I. Y.
« Reply #6 on: June 06, 2003, 04:08:00 PM »
Do your own homework from now on!

kreiselmeier

  • Guest
Thanks for the info...
« Reply #7 on: June 07, 2003, 01:18:00 PM »
Thank you for the help,

I just did not know where to look. I know now, even it is a little confusing, since there is no clear opinion.

To prepare a 1 mol solution of say NaOH (1 Mole = 39.9971g)
do I add this (1 Mole = 39.9971g) to 1 liter of water, or do I add 1 Liter of water to 1 Mole = 39.9971g of NaOH???

And How do I prepare 2.5 N H2SO4???  Shulgin wrote 2,5 N not M. so is it 1.25 mol H2SO4 adding to H2O till I have 1 Liter??
This would be 122.59875 Gramm of H2SO4 in a cylinder and I add Water till I have 1 liter??

Thank you...
And thank you Calcium, for the tip, very encouraging, especially for a newbee. Spitball was equally arrogant, look where he is now...


gabd

  • Guest
Explanation of molarity,molality, normality
« Reply #8 on: June 07, 2003, 08:29:00 PM »
Molarity: Number of moles per liter of solvent

To prepare a 1 molar solution of Sulfuric acid(I know its about 98% but lets assume its 100%)

You need 98 grams dissolved in a total of 1 liter.
Density of sulfuric acid: 1.86
98g / 1.86 g/ml = 52.7 ml of concentrated sulfuric acid.
Add that to lets say 500 ml of water, then complete to 1 liter. There you go, 1 molar solution

Molality: Number of moles per kg of solvent(rarely used).
For water, its pretty much the same since the density is 1g/ml. For other solvent like for example DCM, a solution of 1 molar in dcm would have a molality of  1/1.325 = 0.75

Normality: number of equivalents per liter of solvent.

For H2SO4, there is two protons that can react so there is two equivalent that can react per molecule. So a 1 M H2SO4 solution is a 2N solution.

For NaOH, there is one OH group, one equivalent per molecule. So  a 1 M solution is the same as a 1 N solution.

I hope this helps!

kreiselmeier

  • Guest
This has helped...
« Reply #9 on: June 11, 2003, 02:40:00 PM »
Thank you!