# Popular General Chemistry Topics

Discussion in 'MCAT: Medical College Admissions Test' started by drjene, Jul 21, 2011.

1. ### drjene 2+ Year Member

Joined:
Jul 21, 2011
Messages:
2
Likes Received:
0
Status:
Pre-Medical
In ya'll opinion, what are the most popular general chemistry topics on the MCAT? Like a MUST know topic for the MCAT

Thank you!

2. ### mejorization 7+ Year Member

Joined:
Jun 27, 2010
Messages:
123
Likes Received:
7
MDApps:
Status:
Medical Student
deltaG=deltaH-TdeltaS

Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
3. ### neelyboy 2+ Year Member

Joined:
May 3, 2011
Messages:
46
Likes Received:
0
Status:
Medical Student
MUST KNOW: Henderson Hasselbalch
pH = pKa + log [base/acid] = pKa + log [A-/HA]

if pH < pKa, then the species is more prevalent in the protonated state as there will be a higher concentration of acid (HA) to fit the HH equation

if pH > pKa, then the species will be more prevalent in the deprotonated state as there will be a higher concentration of base (A-) to fit the HH equation

pKa = -log Ka
Ka = 10^-pKa

pH = -log [H+]
[H+] = 10^-pH

For acids/bases:
If it's a strong acid or base, pH = - log[HX]] or pOH = -log[MOH]

If it's weak, pH = 1/2pKa - 1/2log[HA] is the best shortcut to calculate the pH of weak species (Thanks TBR!!!)

For titrations:

pH = pKa at the halfway point for weak species titrated by strong species
and at the equivalence point (where moles acid = moles base) pH = (pKa + pH(of titrant))/ 2

for strong species titrated by strong species, the pH is ALWAYS 7 at the equivalence point.

4. ### salim271 Patience is tough. :/ 2+ Year Member

Joined:
May 21, 2011
Messages:
546
Likes Received:
2
Status:
Pre-Medical
Probably some random questions could show up on molecular geometry. You should at least know the basic ones: linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral. You should know the derivatives for them at least up to tetrahedral (bent, trigonal pyramid, etc). Also remember the bond angles 180, 120, 109.5, etc, and when there are nonbonding orbitals the bond angles are always less than those numbers.

Edit: I like this site http://intro.chem.okstate.edu/1314f00/lecture/chapter10/vsepr.html

5. ### Temperature101 Membership Revoked Removed 2+ Year Member

Joined:
May 27, 2011
Messages:
3,487
Likes Received:
78
Status:
Medical Student
Electrochemistry and sound seem to usually appear on the mcat.

6. ### Donald Juan 7+ Year Member

Joined:
May 22, 2011
Messages:
1,698
Likes Received:
2,592
Status:
Resident [Any Field]
7. ### EnergyDrink 5+ Year Member

Joined:
Apr 3, 2011
Messages:
882
Likes Received:
3
Status:
Medical Student
All of them if you want to get above an 8...

8. ### inquiry101 5+ Year Member

Joined:
Jul 25, 2009
Messages:
107
Likes Received:
3
Status:
Pre-Medical
leave no stone unturned

9. ### centrigeugle less qq, more pew pew 5+ Year Member

Joined:
Jun 23, 2011
Messages:
563
Likes Received:
1
Status:
Medical Student
One thing I'll suggest:

Grow comfortable using dimensional analysis as the ONLY way of solving a problem. Units really are that important.

Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
10. ### bambam02 5+ Year Member

Joined:
Jul 15, 2010
Messages:
116
Likes Received:
0
Status:
Medical Student
LEO the lion says GER

11. ### salim271 Patience is tough. :/ 2+ Year Member

Joined:
May 21, 2011
Messages:
546
Likes Received:
2
Status:
Pre-Medical
This is the MCAT not Chem 101

12. ### CodeBlu Dream Weaver Lifetime DonorVerified Account 7+ Year Member

Joined:
Oct 13, 2010
Messages:
10,987
Likes Received:
114
Status:
Fellow [Any Field]
this x 1000000000000000000 m/s^2

Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
13. ### Whatyousay A few loose screws 7+ Year Member

Joined:
Aug 9, 2009
Messages:
5,802
Likes Received:
57
MDApps:
No one mentioned Le Chatlier's?

Easy to learn, easy to apply, easy to test.

• ### About Us

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.

SDN is published by CRG, a nonprofit educational organization. We’re dedicated to our mission to help you.
• ### Quick Navigation

Open the Quick Navigation

• ### Donate

Donate today!

The volunteer teams works very hard to make sure the community is a valuable resource for all our fellow members. Consider donating today!

We reinvest our revenues into site improvements and development of new resources for the student doctor academic community.

Our content is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. DMCA Reports