User not logged in - login - register
Home Calendar Books School Tool Photo Gallery Message Boards Users Statistics Advertise Site Info
go to bottom | |
 Message Boards » » chemistry... can someone explain this? Page [1]  
attucker23
New Recruit
20 Posts
user info
edit post

How many grams of 50 wt % NaOH (FM 40.00) should be diluted to 1.00 L to make 0.10 M NaOH?

5/29/2006 10:30:49 PM

WOLFeatRAM
All American
1900 Posts
user info
edit post

look in your solution guide OR visit Chem tutorial...that advice got me through two semester of that CH stuff

5/29/2006 10:32:57 PM

attucker23
New Recruit
20 Posts
user info
edit post

no solution guide, anyone else?

5/29/2006 10:33:46 PM

StateIsGreat
All American
2838 Posts
user info
edit post

I'd be able to explain the answer if this were Spring 2004. Alas, that semester is long gone.

5/29/2006 11:18:43 PM

humandrive
All American
18286 Posts
user info
edit post

0.1 M NaOH in 1.00 L means there are 0.1 moles in the solution. (I think thats right)

Well if you knows the # of moles you know the # of atoms and you know the weight of a NaOH atom so you know the weight of NaOH you need. However you only have 50 w% so you need 2*Mass(NaOH) of the 50 w% solution.

5/29/2006 11:25:54 PM

attucker23
New Recruit
20 Posts
user info
edit post

thank you! that worked

5/29/2006 11:31:49 PM

humandrive
All American
18286 Posts
user info
edit post

that part with the moler stuff was the only part I wasn't sure about (it has been ~4 years since I've had chemistry)

5/29/2006 11:42:51 PM

mrjaydubyoo
All American
2310 Posts
user info
edit post

this shit's easy, as i have gotten the tougher proceeding problems....but i cant get this one to save my life....2 submissions left.....any help would be appreciated



A solution is prepared by dissolving 1.7 g CaCl2 in 137.0 g water. What is the freezing point of this solution. Note: kf for water is 1.86oC/m

5/30/2006 9:17:44 PM

humandrive
All American
18286 Posts
user info
edit post

Water freezes at 0 and goes up 1.86 C/mole.


1.7 g CaCl2 | mole | | g H20 | 1.86 C
----------------------------------------------------------
| g CaCl2 | 137 g H2O | L H20 | mole


I'm thinking that the C/mole you mean C/molality but I could be wrong.





[Edited on May 30, 2006 at 10:02 PM. Reason : there]

5/30/2006 10:01:29 PM

mrjaydubyoo
All American
2310 Posts
user info
edit post

the formula for this problem is:

delta*Tf = i*kf*m
=3*-1.86*.117
=-.65 degree Celsius

i got it....my i was wrong...thanks tho

5/30/2006 10:24:29 PM

 Message Boards » Study Hall » chemistry... can someone explain this? Page [1]  
go to top | |
Admin Options : move topic | lock topic

© 2024 by The Wolf Web - All Rights Reserved.
The material located at this site is not endorsed, sponsored or provided by or on behalf of North Carolina State University.
Powered by CrazyWeb v2.39 - our disclaimer.