Gene Lynn

AP Chemistry Tip Line

[Gene Lynn @APChemTipLine]

That wraps up this year's tip line. I hope it helps. Good luck!!

[Gene Lynn @APChemTipLine]

All tips from today
https://t.co/DWrmBrdF2x

[Gene Lynn @APChemTipLine]

For free response questions don't write too much! Just answer the question!

[Gene Lynn @APChemTipLine]

If they ask you to make a choice (higher, lower, increase, decrease) make the choice and write this part down FIRST, justify your answer.

[Gene Lynn @APChemTipLine]

FRQ pacing 20 min per long question (1-3) 10 minutes per short question (4-7). That leaves 5 extra minutes.

[Gene Lynn @APChemTipLine]

The 2-3 pass method is better for kids who struggle with time. You put your time into the ones you know, but it wastes some time. If you don’t know which MC method to use, start with pacing, if you get behind switch to the 2-3 pass method.

[Gene Lynn @APChemTipLine]

MCQ pacing-Answer 10 MCQs in the first 15 min, 20 MCQs in 30 min, 30 in 45 min, 40 in 60 min 50 in 75 min or Do the MC in two to three passes - 1st ones you know are quick, 2nd ones you know that take time, 3rd try the ones you didn’t know.

[Gene Lynn @APChemTipLine]

Don’t spend too long on a MC question. Efficiency is key. Answer all questions Use ONE of the following two strategies for MC

[Gene Lynn @APChemTipLine]

Strong acid means that the conjugate base won’t accept H+. Weak acid means the conjugate base acts as a weak base.

[Gene Lynn @APChemTipLine]

HF is a weak acid, all other halogens make strong acids. Just remember, “get the F out”

[Gene Lynn @APChemTipLine]

Si and SiO2 are giant molecular structures, similar to diamonds

[Gene Lynn @APChemTipLine]

Units of dH and dS are often different, kJ and J. Make sure the units agree before plugging into dG equation

[Gene Lynn @APChemTipLine]

The most electronegative elements F > O > Cl = N (Cl and N are approximately equal)

[Gene Lynn @APChemTipLine]

RTQ ATQ Read the question. Answer the question…And my favorite, ATFQ, Answer the full question.

[Gene Lynn @APChemTipLine]

Volumetric flasks do not need to be rinsed. Add your known chemical and fill to the line to make a solution.

[Gene Lynn @APChemTipLine]

The proper way to use a burette or pipette is to rinse it first with your solution. Adding water would dilute the solution.

[Gene Lynn @APChemTipLine]

When explaining a lab based error, explain that a certain mistake would increase or decrease your calculated value and why.

[Gene Lynn @APChemTipLine]

clean up an acid spill with a carbonate or other safe WB, not an equally corrosive strong base

[Gene Lynn @APChemTipLine]

Periodic trends are not an explanation, instead discuss effective nuclear charge and distance (Coulomb's law)

[Gene Lynn @APChemTipLine]

LeChatelier’s principle is not an explanation in itself. A shift to reduce a stress (K v Q) is.