# help! GC topscore question!!!

Discussion in 'DAT Discussions' started by JustwantDDS, Aug 4, 2011.

1. ### JustwantDDS DrAMG 7+ Year Member

Joined:
Jan 2, 2010
Messages:
664
0
Status:
Dental Student

ok- i understand up to finding the 40% of M

then wth is the rest
an ICE table i assume.......... can someone explain/show set up please?!?!?!?! my brain hurts

2. ### LetsGo2DSchool Removed 2+ Year Member

Joined:
Jul 11, 2009
Messages:
1,191
4
Status:
Pre-Dental
Hey, I just got this problem wrong too a little while ago, but now understand the solution.

It's an ICE setup:

Initial:
PCl5: 4.750 M
PCl3: 0 M
Cl2: 0 M

Change:
PCl5: -1.896 M
PCl3: +1.896 M
Cl2: +1.896 M

Equilibrium:
PCl5: 4.750 - 1.896 = 2.854 M
PCl3: 1.896 M
Cl2: 1.896 M

PCl5 <---> PCl3 + Cl2

Kc = [PCl3][Cl2] / [PCl5]
Kc = (1.896)(1.896) / 2.854
Kc = (1.896)^2 / 2.854

3. OP

### JustwantDDS DrAMG 7+ Year Member

Joined:
Jan 2, 2010
Messages:
664
0
Status:
Dental Student
thank youuuuuuuuuu
how r we supposed to do this w/o a calc errrrrrrrrrrrrrgh

We’ve been on the Internet for over 20 years doing just one thing: providing career information for free or at cost. We do this because we believe that the health education process is too expensive and too competitive.

We believe that all students deserve the same access to high quality information. We believe that providing high quality career advice and information ensures that everyone, regardless of income or privilege, has a chance to achieve their dream of being a doctor.