Welcome Guest Search | Active Topics |

Tag as favorite
Concentration
Options
Previous Topic Next Topic
Josh C
#1 Posted : Friday, July 22, 2011 11:08:20 PM
Rank: Newbie

Groups: Registered
Joined: 5/16/2011
Posts: 2

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Which solution is more concentrated and why? 1 molarity of NaCl, or 1 Molality of NaCl?
I was not clear on this section when it was discussed in the lecture. Help would be greatly appreciated!
Thanks,
JC
Back to top
Report?
matthewward
#2 Posted : Saturday, July 23, 2011 9:50:53 PM
Rank: Instructor

Groups: Registered
Joined: 6/9/2010
Posts: 5
Location: Victoria

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
1M is more concentrated than 1m. Think about it this way:

1M of NaCl could be prepared by taking 1 mol of NaCl and adding it to water until a volume of 1L is reached.

1m of NaCl would be prepared by taking 1 mol of NaCl and 1kg of water (1L) and adding the two together. Technically then, the 1m solution takes up slightly more volume than the 1M solution and even though both solutions have exactly 1 mol of NaCl in them, the 1m solution would be SLIGHTLY less concentrated than the 1M solution.

For all practical purposes the two concentrations are identical (1M and 1m) - but you know the MCAT:) Your EK book does a similiar problem in one of the 24 practice problems from chapter 4 (I believe).
Back to top
WWW
Report?
Users browsing this topic
Guest (3)
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.080 seconds.