Chemistry constants

[jdm199]

Hey folks,

Running through practice problems for the exam in 2 weeks. I've noticed that there are wide ranges from Ksp (solubility product) values in the various references that I have. I've also had a hard time finding some delta-H and delta-G values. I was curious if they will typically provide those numbers on the exam, or if I need an all-inclusive refernce. If I need a reference, any advice on what reference they might be getting their data from, so that I can be on the same page. Hate to get a few problems wrong, because they were working on a different Ksp value.

Thanks!

 

[Dleg]

Yeah, I remember getting all worried about that, too. I even got a copy of that huge CRC book full of chemical properties... can't remember the title now. Even that one didn't match with the constants used in the sample problems, and I got all stressed out about it. But it doesn't matter, because I didn't take it and I didn't need it. I think you will not have to worry about it - that level of constant should be given to you in the problem statement.

That's my take on it, anyway - don't worry about it.

 

[klk]

I agree with Dleg. They should give you all the constants you would need to solve the problem. Otherwise people would end up with significantly different answers and it would be difficult to standardize the results.

 

[RIP - VTEnviro]

Does the ENVRM have standard tables of Delta H, G, and S, and standard Ka, Ksp, etc. values?

I think it does but its been a while. The exam questions are not designed to be open to interpretation. Values will either be given or be commonly available in standardized tables.

If you don't have a good envl chem book, you can download this stuff online.

 

[jdm199]

Thanks for the replies. After thinking about it some more, I agree that they can't get into a situations with varying constants. I also started running through some practice problems from the NCEES practice exam and they gave the constants.

EERM does have some Del-G and Del-H values, but for only a few compounds.

 

[RIP - VTEnviro]

The exam is not concerned about you memorizing enthalpy tables or reaction constants. It tests whether you can apply data either given or readily available in a standard table to solve a problem.

There are too many ranges of values and different standards to give a uniform, relevant test otherwise.