5 Steps to a 5 AP Chemistry

Experimental  279

You calculatethe change in temperature from your measured initial and final

temperatures. You do not need to give a lot of detail when listing the

required measurements, but you need to be very specific in what you

measure. Many students, have lost exam points for not clearly distinguishing

between measured and calculated values.

The basic calculations fall into two categories. Simple calculations, such as

the change in temperature or the change in volume, are the easiest to forget.

Simple calculations may also include mass-to-mole conversions. The other

calculations normally involve entering values into one of the equations given

at the beginning of the previous chapters of this book.

Beginning with the 2007 AP Chemistry exam, experimental questions may

be incorporated into any of the free-response questions. This means that

you will need to have a good understanding of the experiments in order to

discuss not only the experiment itself, but the underlying chemical concepts.

Therefore, when studying each experiment, refer back to the appropriate

material to review the concepts involved.

Keywords and Equations

Pay particular attention to the specific keywords and equation in the chapters

associated with the individual experiments.

A=abc(A=absorbance;a=molar absorbtivity; b=path length;

c=concentration)

analytical balance

buret

capillary tubes

crucible and cover

drying oven

evaporating dish

forceps

hot plate

Meker burner

pipet

rubber tubing

stopwatch

test-tube rack

triangle crucible support

wash bottle

wire gauze

barometer

burner

centrifuge

cuvettes

electrodes

filter crucibles

and adapters

funnel

ice

mortar and pestle

power supply (battery)

spectrophotometer

support stand

thermometer

voltmeter

watch glass

beaker(s)

calorimeter

clamp

desiccator

Erlenmeyer flask

filter flasks

graduated cylinder

ion exchange resin

or silica gel

pH meter

Pt or Ni test wire

stirrer

test tube(s)

tongs

volumetric flask

water bath

KEY IDEA

Experiment 1: Finding the Formula of a Compound

Synopsis

The formula of a compound is determined by using the mass of the original substance,

usually a metal, and the mass of a compound of that substance, usually an oxide. (See the

chapter on Stoichiometry.)

Equipment

analytical balance burner crucible and cover

support stand tongs triangle crucible support