I HATE GEN. Chemistry!

[grifgin]

Advertisement - Members don't see this ad

Am I the only one here who just hates this stupid section on the DAT!
what should I do to get a good mark on it? I just cant get my head around it!


BTW, I love Orgo Chem

 

[Mackerel]

I dont know it seems like after awhile you cant learn anything new in Gen Chem whereas you'll never know enough for bio

 

[whiskeysour]

I dont know it seems like after awhile you cant learn anything new in Gen Chem whereas you'll never know enough for bio

exactly.

 

[golfmontpoker]

u arent the only one... Gchem will probably be my lowest score on this test! I HATE it!

 

[BallDontLie]

If you havent already, I'd recommend taking physical/analytical chemistry. It's a tough class, but it'll make gen chem on the DAT a whole heck of a lot easier. I was taking that class the same time I was studying for the DAT. At the beginning of the semester I was getting 15's and 16's on gen chem. By the end of the semester I was getting 18's and 19's on my Kaplan tests and got a 25 on the real thing.

 

[flylab101]

u arent the only one... Gchem will probably be my lowest score on this test! I HATE it!

I'm having the same problem. I'm going over solubility, gas laws problems now and they are confusing.

 

[Notoriousjae]

i am not a big fan of gen chem either. best way to study for this section is to learn the general concepts and practice as many problems as you can. i used my old G chem textbook from freshman year of college to review everything again.

 

[toccata]

I wasn't a big fan of gen chem either.. and I aced it on DAT! 😀
I can't believe how I did it! Just keep doing problems until you
are confident. Good luck!

 

[DesiDentist]

I hated gen chem, ochem and quantitative reasoning.

For gen chem I remember I did the following. I bought the gen chem video tapes by standard deviants those gave me a somewhat comfortable feeling about the topics. Then I bought an SAT II book ( Princeton review). SAT II books are very short and they contain simple to medium level problems. I did as many as I could. Then I moved onto Kaplan material which I still felt was way too hard, much harder than the real exam.

Good luck,

DD

 

[beastly115]

Gen chem will be my worst section also. I had a _horrible_ professor and didn't learn _anything_ when I took the class so alas, I am teaching myself the entire years worth of material.

 

[FatalExtraction]

gen chem is definitely not fun for me...It's all the word problems I dont like in math, but in another language I can't understand mixed in with more abstract concepts...

does anyone know how to calculate the pH when they ask for it on the DAT? how do you do it without using a calculator and taking the neg. log of [H+]?

 

[fancymylotus]

they have all those log law shortcuts in the margins of the kaplan books( that n-logX thing,etc).

as for hating gchem,sign me up on that list,too! ive resigned myself to the fact that i 1)cant stand it, and 2) will not be able to teach it to myself in the 55 or so days till DAT time. therefore, im just going to memorize as much as possible and do every problem i can get my hands on,and hope for the best. ive been doing really well on bio/orgo/rc/qr so maybe those scores will balance out the chem one.

back to the books :/ good luck guys!

 

[hpets]

the AP chem book from princeton is helping me break down the gen chem area since i am pitifully bad, you might want to check it out (i borrowed mine from the local library, but i think its a good investment for those fearing this section). i still fear moles, but not as much as i did a few days ago.

 

[Notoriousjae]

is it just my experience or are most chem/ochem professors complete egoistic, unsympathetic, worthless D**kheads? i didnt have good chem or ochem professors at my university which is why i have to teach myself all this crap over but its been going good so far

 

[armorshell]

is it just my experience or are most chem/ochem professors complete egoistic, unsympathetic, worthless D**kheads? i didnt have good chem or ochem professors at my university which is why i have to teach myself all this crap over but its been going good so far

Not all of them are, I had fantastic professors for both gchem and ochem, of course I went to community college 😉

 

[Hopin']

Am I the only one here who just hates this stupid section on the DAT!
what should I do to get a good mark on it? I just cant get my head around it!


BTW, I love Orgo Chem

You aren't the only one... I was in the same boat.... I hated Gen Chem. It was so confusing and I wouldn't know what to do on certain problems. But you have to go through it... no way out....
BTW... I got the lowest on that section on my Dat's...

 

[LNinlove]

is it just my experience or are most chem/ochem professors complete egoistic, unsympathetic, worthless D**kheads? i didnt have good chem or ochem professors at my university which is why i have to teach myself all this crap over but its been going good so far

I couldn't speak in terms of ochem, but my gen chem I teacher was pretty hardcore. He had no sympathy for those of us that weren't majoring in chem. My chem II teacher is really cool and is pretty helpful. In addition I would say that he partakes in his own fair share of ether.

For the gen chem I teacher, I talked with him one day in his office and he said that they teach to the top 10% of the class. This guy rarely went over the math problems, he usually just threw them at us and let us fend for ourselves....

 

[jmick101]

You know, I dont find getting the pH to be all that difficult without a calculator. A practice problem may say: find the pH of a solution that contains 5.2 x10^-5 of H ions. Here is the way that I approach this question:
The first thing is to know that the pH is going to be the anti log of 5.2 plus the anti log of 10^-5. The anti log of 10^-5 is 5, that is pretty easy.

The hard part comes in finding the anti log of 5.2. To find this is not so easy unless you have a logarithm table, but if you look at the table you see a sort of pattern. That pattern, which will get you close enough for government work, is that the log of a number between 1 and 10 is that number plus one with a decimal in front of it. IE log5.2 will ROUGHLY equal .52 + .1= .6. I put it out as a caveat that is method is a pretty rough approximation, but it will get you close enough.

Then you take the anti log of 5.2 (-.6) plus the anti log of 10^-5 (5) and you get the pH, 4.4. Its down and dirty, but it works. Hope it helps.

gen chem is definitely not fun for me...It's all the word problems I dont like in math, but in another language I can't understand mixed in with more abstract concepts...

does anyone know how to calculate the pH when they ask for it on the DAT? how do you do it without using a calculator and taking the neg. log of [H+]?

 

[Uracil]

That was extremely helpful thanks!

My advice to do good in general chemistry is to actually believe in yourself and be willing to truly understand the problems. I hate gen. chem with passion and took it a looong time ago in my freshmen year. I had to go back and relearn everything once again to do good on the DAT.

Gen. chemistry was a whole another language to me, but I started from the bottom and most of the stuff came back, even when I thought I wouldn't be able to remember anything.

Gen. chem is my weakest subject, so I've been doing problems and studying day and night until I get sick of it. 😡 and now I've been doing much better in the problems..

Don't give up guys! 👍

 

[hopelessdoc]

since we takin bout gchem...can someone plzzz explain how to do those resonance problems??? wait is it ochem?? whatever...I just remem those quest...which is the most stable comp out of all this choices...when I looked at the answers I understand but when I face similar one again...I just can't do it..??
thanx.,,

 

[Notoriousjae]

🙄

since we takin bout gchem...can someone plzzz explain how to do those resonance problems??? wait is it ochem?? whatever...I just remem those quest...which is the most stable comp out of all this choices...when I looked at the answers I understand but when I face similar one again...I just can't do it..??
thanx.,,

umm so whats the question? 😕

LNinLove, my gen chem I professor was just as bad as yours was if not more. For some reason it has been my experience that chem profs seem to think all high and mighty of themselves but i'm sure theres good profs out there as well. i just havent come across them 🙄

 

[JohnDoeDDS]

since we takin bout gchem...can someone plzzz explain how to do those resonance problems??? wait is it ochem?? whatever...I just remem those quest...which is the most stable comp out of all this choices...when I looked at the answers I understand but when I face similar one again...I just can't do it..??
thanx.,,

You need to calculate the formal charge. I dont want to sound cocky but it is real easy... Watch: You want to have the lowest possible charge on the whole molecule around each element...

The way to calculate FC is you take the number of valence electrons that element has and start subtracting. YOu subtract 1 for every bond and 1 for every unpaired electron. Move around the bonds to get each element as close to 0 as possible.

 

[bevzi]

I took Physical chemistry last Fall and i still got a low grade on a Practice Test. I need to spend five more hours to finish the section on Chemistry in Kaplan. So can you tell us if there were more questions based on Termochemistry, phase/phase changes on the DAT test?

If you havent already, I'd recommend taking physical/analytical chemistry. It's a tough class, but it'll make gen chem on the DAT a whole heck of a lot easier. I was taking that class the same time I was studying for the DAT. At the beginning of the semester I was getting 15's and 16's on gen chem. By the end of the semester I was getting 18's and 19's on my Kaplan tests and got a 25 on the real thing.

 

[armorshell]

You need to calculate the formal charge. I dont want to sound cocky but it is real easy... Watch: You want to have the lowest possible charge on the whole molecule around each element...

The way to calculate FC is you take the number of valence electrons that element has and start subtracting. YOu subtract 1 for every bond and 1 for every unpaired electron. Move around the bonds to get each element as close to 0 as possible.

Or more simply, try to make sure every element has an octet 😉

 

[Notoriousjae]

You need to calculate the formal charge. I dont want to sound cocky but it is real easy... Watch: You want to have the lowest possible charge on the whole molecule around each element...

The way to calculate FC is you take the number of valence electrons that element has and start subtracting. YOu subtract 1 for every bond and 1 for every unpaired electron. Move around the bonds to get each element as close to 0 as possible.

FC= # of valence electrons - (#lone pair electrons + 1/2 #bonding electrons)

Just thought it'd be easier in equation form. sorry didnt understand what hopelessdoc wrote at first.

 

[jmick101]

As far as formal charges go, the way I remember it is:
Should - has. For instance the formal charge on Nitrogen in NH3 is
It SHOULD have 5 Valence e's it HAS 5, so the formal charge is zero. A simple mnemonic, but it works.

 

[FatalExtraction]

hey thanks jmick for the tip ill def. practice that one...now if only someone could cure me of doing stupid mistakes on this test id be golden...i am the MASTER at making stupid mistakes heh

 

[armorshell]

hey thanks jmick for the tip ill def. practice that one...now if only someone could cure me of doing stupid mistakes on this test id be golden...i am the MASTER at making stupid mistakes heh

Oh man, tell me about it. At this point in my studying, every question I miss on genchem is due to me doing one of these two things:

A. Reading the *@*$& question wrong
B. Making a really stupid math error

I just need to have someone beat these out of me!

 

[fancymylotus]

Oh man, tell me about it. At this point in my studying, every question I miss on genchem is due to me doing one of these two things:

A. Reading the *@*$& question wrong
B. Making a really stupid math error

I just need to have someone beat these out of me!

haha the worst is when i get the whole complicated problem right...as in set the entire damn thing up and then divide wrong cause my estimation is off..lsdkjflksdjfds!

 

[JohnDoeDDS]

FC= # of valence electrons - (#lone pair electrons - 1/2 #bonding electrons)

Just thought it'd be easier in equation form. sorry didnt understand what hopelessdoc wrote at first.

This doesnt take into account lone electrons. What if its not a pair... Also I think if it is a lone pair than you wold subtract 2, no?

 

[Notoriousjae]

This doesnt take into account lone electrons. What if its not a pair... Also I think if it is a lone pair than you wold subtract 2, no?

If you had a lone electron, would you not have the wrong lewis structure because you are violating the duet and octet rule?
i did make a mistake in the eq though its supposed to be
FC= # of valence electrons on free atom - (#lone pair electrons + 1/2 #bonding electrons)
where (#lone pair electrons + 1/2 #bonding electrons) would give you the number of valence electrons assigned to the atom in the molecule.

 

[JohnDoeDDS]

If you had a lone electron, would you not have the wrong lewis structure because you are violating the duet and octet rule?
i did make a mistake in the eq though its supposed to be
FC= # of valence electrons on free atom - (#lone pair electrons + 1/2 #bonding electrons)
where (#lone pair electrons + 1/2 #bonding electrons) would give you the number of valence electrons assigned to the atom in the molecule.

I dont think so. Im pretty sure you can have a single electron to complete the octet rule on an atom. Someone correct me if Im wrong please.

I just think of it as subtracting 1 for each bond that way I dont have to divide anything by half.

SO basically its the valence minus number of non-bonding electrons minus the number of bonds.

So if you have a lone pair you would have 2 non-bonding electrons and would end up subtracting 2 not 1...

 

[EmanUT]

Focus on Kaplan's chemistry and you should do fine on that section. I only looked at the Kaplan stuff (book, subject tests and practice tests) and got 20+ on the real DAT chemistry.

 

[Notoriousjae]

I dont think so. Im pretty sure you can have a single electron to complete the octet rule on an atom. Someone correct me if Im wrong please.

I just think of it as subtracting 1 for each bond that way I dont have to divide anything by half.

SO basically its the valence minus number of non-bonding electrons minus the number of bonds.

So if you have a lone pair you would have 2 non-bonding electrons and would end up subtracting 2 not 1...

johndoe you might be right. i dont quite follow your line of reasoning so i dont know but if it works out for you in getting the correct answer then it really doesnt matter. I am going by what i learned in my gen chem textbook. Using the equation i put up makes perfect sense to me when i work on formal charges of atoms within a molecule based on a given lewis structure.

 

[armorshell]

This doesnt take into account lone electrons. What if its not a pair... Also I think if it is a lone pair than you wold subtract 2, no?

When calculating formal charge you take into account every electron on the atom. So, for lone pairs and radicals you would count 1 for each electron. For covalently bonded electrons you would count 1 for each bond, as it is assumed the 2 bonding electrons are shared equally. This number is then compared to the number of valence electrons on the free atom to determine the formal charge.

For example:

Cl- has 8 non-bonding electron, free Cl has 7 valence electrons, 7-8 = -1

CH4 has 8 bonding electrons, but for formal charge we count 4. Free carbon has 4 valence electrons, 4-4 = 0

For a radical example:

CH3* had 6 bonding electron, but we count 3. It has 1 unpaired electron. Free carbon has 4 valence electrons, 3+1-4 = 0

 

[BallDontLie]

I took Physical chemistry last Fall and i still got a low grade on a Practice Test. I need to spend five more hours to finish the section on Chemistry in Kaplan. So can you tell us if there were more questions based on Termochemistry, phase/phase changes on the DAT test?

yea there were some thermo and phase questions, but they were pretty basic. Nowhere near the depth and detail of pchem. In fact, gen chem I is probably sufficient for what you get on the DAT. Notice I say sufficient, but not excellent. My point is that by going through the tough stuff in pchem, you will be better at the themo on the DAT cuz it will seem like a walk in the park compared to what you get in pchem.

 

[JohnDoeDDS]

yup we are talking about the same thing just in different ways.

 

[drdmddds]

I have some subject tests (gchem included) in pdf form that I am selling if anyone is interested pm me.

$20 gets you...
bio
gchem
orgo
rc
qr
integative test (full length sci and rc)
pat (all sections)

I have ~ 5 tests per subject and they all have detailed answers, it was the most useful thing i used when studying for the DAT.