Approaching General Chemistry Questions?

[pandalove89]

Do you guys have an easy way to approach general chemistry questions.

I feel like whenever I first start reading a general chemistry problem on the DAT destroyer I get completely lost as to what they're asking.

For example:
Consider the following reactino:

4H+ (aq) + O2 (g) + 4 e- <-- --> 2H2O (l)
If sodium hydroxide is added, and assuming O2 (g) is at 1 atm and [H+] = 1.0 M, which statement is true?

a) The E value would not change since base is not a part of this system
b) E value would increaes
c) The reaction quotient would take H2O (l) into account
d) two of these are true
e) none ofthese are true


Supposedly, we're supposed to use the Nernst Equation, but there was no way I would've even guess to use that.

So what I'm trying to say is, if the Gen Chemistry portion gave me some equations to first work with, it would be much easier for me. Do you guys have any strategies to immediately find how to first solve a gen chem question at first glance?

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[pandalove89]

bump

 

[reely989]

bump

That would be a pretty vague question, but it really comes down to noticing the fact that they go ahead and give the number of electrons transferred. That, combined with their assumption that you are familiar with most general chemistry formulas, and it isn't unreasonable for them to expect you to be able to deduce the nernst equation is used. It's just memorizing all the formulas, knowing what each item in the equation stands for, and being able to quickly recognize what kind of problems it could apply to.

The more problems you do, it will become easier. But don't just memorize a huge list of equations out of context, learn them by doing problems related to them and why they matter. In my opinion, a majority of general chemistry is just simple repetition. Once you start seeing the same material over and over, it becomes much easier to associate a problem to the correct equation.

 

[Golfguy]

Do you guys have an easy way to approach general chemistry questions.

I feel like whenever I first start reading a general chemistry problem on the DAT destroyer I get completely lost as to what they're asking.

For example:
Consider the following reactino:

4H+ (aq) + O2 (g) + 4 e- <-- --> 2H2O (l)
If sodium hydroxide is added, and assuming O2 (g) is at 1 atm and [H+] = 1.0 M, which statement is true?

a) The E value would not change since base is not a part of this system
b) E value would increaes
c) The reaction quotient would take H2O (l) into account
d) two of these are true
e) none ofthese are true


Supposedly, we're supposed to use the Nernst Equation, but there was no way I would've even guess to use that.

So what I'm trying to say is, if the Gen Chemistry portion gave me some equations to first work with, it would be much easier for me. Do you guys have any strategies to immediately find how to first solve a gen chem question at first glance?

This question is tricky. But you can solve it without the nernst equation. Adding OH- will react with the H+, and drive the reaction to the reactants (forming H20, and dropping out of the Keq or Q ratio). The Nernst equation simply shows mathematically how it works out.

Don't let this problem deter you, I don't think it's representative of what you'll find on the exam.

 

[hell0k1tty]

If you need help with gen chem, check out chads videos. He explains everything so well that eventually, you'll look at the questions and know exactly how to approach it. I was NEVER strong in gen chem but his videos helped me LOTS for the DAT. Good luck!