PCAT Chemistry Section

[delano2000]

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I wanted to know if I have to memorize all these equations for the PCAT. For example, do I need to memorize the equation to calculate electromagnetic energy, or should I be more familiar with equations on how to calculate entropy and enthalpy etc.? I am really confused.

 

[roziak]

I got an 88 on chem and I don't really remember memorizing many equations... August 22nd seems so long ago!

I distinctively remember:

Delta G= DeltaH - T*DeltaS. (goose hunters take shotguns)
DeltaH(rxn)=(Sum of DeltaH(products))-(Sum of DeltaH(reactants)) (important)
DeltaG=-RTlnK
Keq= /[A] when A-->B (important)
rate=k[A]^x^y when aA+bB---->cC+dD (X+Y=order of reaction) (important)
q=m*C*DeltaT (important)
C=frequency*wavelength
E=planck's constant*frequency
PV=nRT (important)
P1V1/n1T1=P2V2/n2T2 (important)
mole fraction, X1=mol1/moltotal
grahams law of effusion/diffusion, rate1/rate2=(M2/M1)^1/2
huckels rule, 4n+2=must be a positive integer for aromaticity
molality (important)
molarity (important)
freezing point depression/boiling point elevation DeltaT=k*m (important)
Electromotive Force, Ecell=Ered+Eox (important)


I didn't memorize the halflife equation because honestly you can figure that answer out my sheer common sense (if something has a halflife of 1day, after 3 days there is now=1/8). Also, with nuclear chem, memorize alpha/beta/gamma/positron/electron capture.

I think that's it for the equations I memorized. I had this written down on a piece of paper on my desk so I just grabbed it and wrote them all down. Now, I have a online copy of all the equations too 🙂

The ones I put (important) after, I distinctively remember using them on the PCAT. Good luck

 

[delano2000]

I got an 88 on chem and I don't really remember memorizing many equations... August 22nd seems so long ago!

I distinctively remember:

Delta G= DeltaH - T*DeltaS. (goose hunters take shotguns)
DeltaH(rxn)=(Sum of DeltaH(products))-(Sum of DeltaH(reactants)) (important)
DeltaG=-RTlnK
Keq= /[A] when A-->B (important)
rate=k[A]^x^y when aA+bB---->cC+dD (X+Y=order of reaction) (important)
q=m*C*DeltaT (important)
C=frequency*wavelength
E=planck's constant*frequency
PV=nRT (important)
P1V1/n1T1=P2V2/n2T2 (important)
mole fraction, X1=mol1/moltotal
grahams law of effusion/diffusion, rate1/rate2=(M2/M1)^1/2
huckels rule, 4n+2=must be a positive integer for aromaticity
molality (important)
molarity (important)
freezing point depression/boiling point elevation DeltaT=k*m (important)
Electromotive Force, Ecell=Ered+Eox (important)


I didn't memorize the halflife equation because honestly you can figure that answer out my sheer common sense (if something has a halflife of 1day, after 3 days there is now=1/8). Also, with nuclear chem, memorize alpha/beta/gamma/positron/electron capture.

I think that's it for the equations I memorized. I had this written down on a piece of paper on my desk so I just grabbed it and wrote them all down. Now, I have a online copy of all the equations too 🙂

The ones I put (important) after, I distinctively remember using them on the PCAT. Good luck

Thank you, thank you, thank you. This was what I was looking for.

I really appreciate the help.🙂

 

[roziak]

no problem. good luck in the next few weeks

 

[phathead]

Also they like to use very round numbers.

The worst thing I had to use to calculate something was the value of R

 

[delano2000]

Also they like to use very round numbers.

The worst thing I had to use to calculate something was the value of R

What do you mean by that?

 

[phathead]

What do you mean by that?

like if you have an ideal gas law problem the numbers they'll give you are something like

PV=nRT
P = 100 atm
V = 1 L
T = 300 K

just that kind of stuff. they won't give you overly complicated math to do, you won't see a value of like 124.2. Like I said the worst thing is using the value of R. Which really isn't that bad lol

 

[roziak]

Yeah. The numbers they give you usually come out to be nice solid integers. For an ex:

A+B-->2C

If there is 32g of A, calculate how many grams of C there will be after the reaction goes to completion (molar mass of A is 32g/mol, molar mass of C is 20g/mol)

You can see how the 32grams easily converts into 1mole. To which you should be able to easily see that 1mole of A will be 2moles of C and a subsequent 2x20g = 40g C.

All the calculations will be similar to this, where you get a nice number for your answer. They are testing you to see if you know the concept and equation, not your arithmetic... that's for the quantitative ability section!

 

[tiff247]

I got an 88 on chem and I don't really remember memorizing many equations... August 22nd seems so long ago!

I distinctively remember:

Delta G= DeltaH - T*DeltaS. (goose hunters take shotguns)
DeltaH(rxn)=(Sum of DeltaH(products))-(Sum of DeltaH(reactants)) (important)
DeltaG=-RTlnK
Keq= /[A] when A-->B (important)
rate=k[A]^x^y when aA+bB---->cC+dD (X+Y=order of reaction) (important)
q=m*C*DeltaT (important)
C=frequency*wavelength
E=planck's constant*frequency
PV=nRT (important)
P1V1/n1T1=P2V2/n2T2 (important)
mole fraction, X1=mol1/moltotal
grahams law of effusion/diffusion, rate1/rate2=(M2/M1)^1/2
huckels rule, 4n+2=must be a positive integer for aromaticity
molality (important)
molarity (important)
freezing point depression/boiling point elevation DeltaT=k*m (important)
Electromotive Force, Ecell=Ered+Eox (important)


I didn't memorize the halflife equation because honestly you can figure that answer out my sheer common sense (if something has a halflife of 1day, after 3 days there is now=1/8). Also, with nuclear chem, memorize alpha/beta/gamma/positron/electron capture.

I think that's it for the equations I memorized. I had this written down on a piece of paper on my desk so I just grabbed it and wrote them all down. Now, I have a online copy of all the equations too 🙂

The ones I put (important) after, I distinctively remember using them on the PCAT. Good luck

You are amazing.... Thanks for giving that information!!!!👍

 

[chitvu]

When I read the booklet information for the PCAT, they say calculator is not permitted. What does it mean? We can't use calculator at all? How come we solve all those problems, 37 secs/each without calculator? I'm scared. Help!!!!

 

[delano2000]

When I read the booklet information for the PCAT, they say calculator is not permitted. What does it mean? We can't use calculator at all? How come we solve all those problems, 37 secs/each without calculator? I'm scared. Help!!!!

No calculators are allowed. You will just have to work around that.

 

[delano2000]

OK. So they are more interested in seeing how much you know the concept and can apply it.

 

[roziak]

yessir!

When's the PCAT? Oct. 17th?

 

[LABruin4Life]

I can't remember, but do they give us a periodic table?

 

[Twiggy1]

unfortunately, no

 

[LABruin4Life]

Bugger...Then what do you guys recommend we memorize regarding the periodic table? EN's? Oxidation numbers? Valence e-'s? etc?

 

[roziak]

Bugger...Then what do you guys recommend we memorize regarding the periodic table? EN's? Oxidation numbers? Valence e-'s? etc?

Yes. Along with trends for ionization energy/electron affinity, electron configuration, atomic radii size, groups (alkali, alkaline earth, halogens, noble gases, transition metals, metals, nonmetals), acidity/basicity strength.

 

[delano2000]

Damn that sucks. Do they include the atomic weight and so on in the questions?

 

[Ruthless]

wait, a periodic table is not provided? How will be know the atomic numbers and masses and element locations?

 

[roziak]

they will give it to you in the problem

 

[Ruthless]

they will give it to you in the problem

how about for trend problems?

 

[delano2000]

they will give it to you in the problem

Well at least we are given the pertinent info. I can live with that.

 

[roziak]

how about for trend problems?

I don't believe so.... Just remember where C, N, O, and all halogens are at for the trend problems... knowing which elements are in group Ia, IIa, and VIIIa would be good too.

 

[Moni526]

Damn that sucks. Do they include the atomic weight and so on in the questions?

Yes, they will include the weights. Thank gosh! haha

 

[delano2000]

Yes, they will include the weights. Thank gosh! haha

Yea thank God. Studying for the PCAT is one thing but having to memorize the info for each element would be ridiculous.

 

[socalpharm86]

how about for trend problems?

Start memorizing the important trends now if you've forgotten. Trends are among the most basic concept that a beginning chemistry student learns

I got an 88 on chem and I don't really remember memorizing many equations... August 22nd seems so long ago!

I distinctively remember:

Delta G= DeltaH - T*DeltaS. (goose hunters take shotguns)
DeltaH(rxn)=(Sum of DeltaH(products))-(Sum of DeltaH(reactants)) (important)
DeltaG=-RTlnK
Keq= /[A] when A-->B (important)
rate=k[A]^x^y when aA+bB---->cC+dD (X+Y=order of reaction) (important)
q=m*C*DeltaT (important)
C=frequency*wavelength
E=planck's constant*frequency
PV=nRT (important)
P1V1/n1T1=P2V2/n2T2 (important)
mole fraction, X1=mol1/moltotal
grahams law of effusion/diffusion, rate1/rate2=(M2/M1)^1/2
huckels rule, 4n+2=must be a positive integer for aromaticity
molality (important)
molarity (important)
freezing point depression/boiling point elevation DeltaT=k*m (important)
Electromotive Force, Ecell=Ered+Eox (important)


I didn't memorize the halflife equation because honestly you can figure that answer out my sheer common sense (if something has a halflife of 1day, after 3 days there is now=1/8). Also, with nuclear chem, memorize alpha/beta/gamma/positron/electron capture.

I think that's it for the equations I memorized. I had this written down on a piece of paper on my desk so I just grabbed it and wrote them all down. Now, I have a online copy of all the equations too 🙂

The ones I put (important) after, I distinctively remember using them on the PCAT. Good luck

Excellent Information. Thank you!