5 Steps to a 5 AP Chemistry

296  Step 4. Review the Knowledge You Need to Score High

Comments

The pH values of the solutions may be used in several ways, depending upon the goal of

the experiment.

Experiment 20: An Electrochemical Series

Synopsis

The reactivity of several metals with solutions containing ions of other metals is observed.

This experiment involves the development of an activity series. (See the Reactions and

Periodicity chapter.)

Equipment

beaker(s) forceps graduated cylinder

test tube(s) test tube rack

Measurements

This experiment is based on observations, not measurements.

Calculations

Observations, not calculations, are needed.

Comments

The more active metal will displace a less active metal from a solution.

Hydrogen is usually included in the series by using acids.

Experiment 21: Electrochemical Cells and Electroplating

Synopsis

Electrochemical cells are constructed, and their cell potentials are determined with a volt-

meter. Electroplating is accomplished by using an external power supply, usually a battery,

to plate a metal onto an electrode. (See Electrochemistry chapter.)

Equipment

beaker(s) electrodes filter crucibles and adapters

filter flasks power supply (battery) test tube(s)

voltmeter

Measurements

The cell potentials are measured with a voltmeter. Refer to the figure of the electrochemical

cell in Chapter 16.

Calculations

Normally, no calculations are required.

Comments

Cells may vary in composition or concentrations.