<p>How good, in terms of difficulty or similarities to the current AP Chem exam, are tests before 1996?</p>
<p>They will be very similar to the current tests in level of difficulty. The only thing you might be wary of is the seemingly low cutoffs for 5s. I think the 1994 test has a cutoff at 99 for a 5, which is the lowest i've ever heard. In contrast, the 2002 test had a cutoff of about 107, which is the highest i've ever heard, but that test was easier than the other practice ones I took. In any case, the released tests contain questions altered to be suitable to current testing situations (for example, they have altered the numbers so that you don't have to use your calculator on the multiple choice section of the 1994 test), but overall, the free response have not changed in difficulty. Areas of chemistry have been added and removed over the years, with the most recent addition probably being the integrated rate law, so you might not see some stuff you will see on the 2006 test on those older tests. I'm not sure if older tests also include the molecular orbital model, but an older version of REA has the molecular orbital model in there, so be ready for some stuff you might never have seen nor will see on the 2006 test.
In any case, the pre-1996 tests will be good preparation for the 2006 tests.</p>