Adrian Dingle’s Chemistry Pages - The Blog

The time crunch in 2010/11

Quite a number of people have asked me about the issue of completing the content of the AP course now that the AP Chemistry exam has been moved forward by eight days in the 2011 AP exam calendar. The question usually starts by someone asking, “What can I leave out?” The answer that I always give is, “Nothing”! What do I mean by that? Well, if you were teaching the course as a preparation for the AP exam you should only be delivering the essential stuff ANYWAY! Your content should really already have been pared down to the bare minimum, and be completely focused. Since I teach AP chemistry to sophomores in one year, we already deliver a pretty efficient model, but even I am looking for more areas to trim the fat. Here’s what I suggest as areas that can be examined for potential time saving.

• Drop the significant figure, rounding and scientific notation nonsense from the beginning of the course. Kids in an AP chemistry class should be able to do this in their sleep, and if there really are some serious problems here then these students’ have no business being in such a class. I haven’t taught this as part of my AP class in years.

Also see; http://adriandingleschemistrypages.com/AdrianDinglesChemistryBlog/nfblog/?p=33

• As long as you are fulfilling your professional obligation in terms of doing what you said you would do in your audit, I strongly suggest paring labs to a minimum. Whilst lab work is clearly an important part of the course, it can be argued that it gives the least “bang for the buck” in terms of time consumed versus concepts taught.

• Net Ionic Equations. Given the horrible demise of this section of the exam in recent years, I am beginning to wonder if my comprehensive treatment of complex REDOX reactions in acid and base, and some esoteric discussions about disproportionation, esterification, organic addition, transition metals and other interesting but more challenging reactions, is going to continue. It simply seems no longer necessary, and whilst it could be argued that these areas were already at the periphery, there was a time when I would not have been able to sleep at night if I had not taught them - the contemporary AP exam seems to suggest I will sleep easier with a “dumbed-down” NIE treatment.

Also see; http://adriandingleschemistrypages.com/AdrianDinglesChemistryBlog/nfblog/?p=18

• Assign more homework BUT grade it. If you want the kids to do more on their own, show that you value that work by collecting it and grading it for accuracy.

• Even if you ARE already down to the bare minimum in terms of content, do one less example problem in some less important topics.

• Be both critical and flexible of yourself and your teaching, EVEN IF YOU ALREADY HAVE A GREAT MODEL THAT HAS BEEN INCREDIBLY SUCCESSFUL. Potentially, this is the most important piece of advice that one can give an experienced practitioner.

As ever, it will be May before we know it and organization and a schedule that you stick to with a bloody-minded, unswerving determination will be an essential, central part of whatever you decide to deliver.

AP Scores 2010 - Best EVER!

The AP scores for my chemistry classes have now been received and the average score is the best that my students have ever recorded. A total of 34 students scored 31 “5’s” and 3 “4’s” for an average of 4.91.

Nice work and congratulations to all.

Subscriber Updates

All relevant subscribers have had the 2010 AP Worked Answers added to their subscriber areas.

Subscriber Updates

Organic materials in TOPICS 1-5 have been updated in the relevant subscriber areas.

2010 Exam Comments and DRAFT Answers

Below you will find my comments on the 2010 AP chemistry exam, and my DRAFT answers. PLEASE NOTE: The answers are my first draft and I will be very happy to receive comments and corrections. Thanks go out to an AP reader for taking a look and making suggestions - you know who you are.

Comments:

Question 1:
Standard fare. Lacks much imagination, I’m afraid.

Question 2:
Very, very easy.

Question 3:
Very, very easy.

Although it makes no difference to the question, the production of Mn3+ in the half-reaction where manganate(VII) is an oxidizing agent, seems a little esoteric and unnecessary to me. Now, perhaps under some circumstances it DOES do that, but in every reference I have ever seens at this level I have only ever witnessed it turning into Mn2+. In addition, Greenwood & Earnshaw, Chemistry of the Elements (known as the “green brick” and my go to guide on such matters) suggests that Mn2+ is the usual product. (G&E DOES mention that one “preparative route” to Mn3+ is “reduction of KMnO4″, but it also notes that Mn3+ has a “marked tendency to disproportionate”. My gripe here is NOT really about the chemistry (whatever it may be), but rather about the wisdom of suddenly having Mn3+ turn up as a product of the acid reduction of Mn7+ instead of (infinitely more usual) Mn2+. It seems like an unncessary diversion and something that could confuse potentially excellent candidates. It just doesn’t make much sense to me.

Question 4:
It seems as though the question writers have given up on this part of the exam. Possibly the easiest EVER? Why GIVE the colors in (a)(ii)? Why tell the kids a gas is produced in (c)(i)? The astonishing decline of complexity in this question in recent years is mildly depressing.

Question 5:
Very, very standard/easy.

(c) Delighted than ethanoic acid seems to finally be supplanting “acetic acid”! Hooray!

Question 6:
Very, very standard/easy.

If this represents a comprehensive and vigorous examination of the best, and highest level of chemistry being taught in American high schools then I think that we have a problem. I remain a HUGE supporter of the public examination/standardized test and its place, but this test simply does not add up to much of challenge at all. Quite weak and disappointing.

ANSWERS

Subscriber Updates

Answers to AP Worksheet 16a have been updated in the relevant subscriber areas.

Subscriber Updates

The following materials have been updated in the relevant subscriber areas;

AP notes TOPIC 6, AP Worksheet 14s answers and AP Worksheet 16s answers

Subscriber Updates

AP Worksheet 13s has been updated in the relevant subscriber areas.

2008 Multiple-Choice analysis

Following the recent release of the 2008 multiple-choice exam, I have continued my analysis of the released multiple-choice sections here;

2008 Multiple-Choice Comments

It’s worth noting that my analysis of the “possible blanks” is geared toward my own students and the AP course that they have followed and as such may not be especially applicable to other AP chemistry classes.

This is the seventh such breakdown, the others being 1984, 1989, 1994, 1999, 2002 and the Practice Exam from March 2008.

Subscriber Updates

AP Worksheet 15a has been updated in the relevant subscriber areas.