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 |