The Laboratory
15
These skills are usually tested on the SAT Subject Test in Chemistry. You
should be able to...
Name, identify, and explain proper laboratory rules and
procedures.
Identify and explain the proper use of laboratory equipment.
Use laboratory data and observations to make proper
interpretations and conclusions.This chapter will review and strengthen these skills. Be sure to do the
Practice Exercises at the end of the chapter.
Laboratory setups vary from school to school depending on whether the lab is
equipped with macro- or microscale equipment. Microlabs use specialized
equipment that allows lab work to be done on a much smaller scale. The basic
principles are the same as when using full-sized equipment, but microscale
equipment lowers the cost of materials, results in less waste, and poses less
danger. The examples in this book are of macroscale experiments.
Along with learning to use microscale equipment, most labs require a student
to learn how to use technological tools to assist in experiments. The most common
are:
Gravimetric balance with direct readings to thousandths of a gram instead
of a triple-beam balance
pH meters that give pH readings directly instead of using indicators
Spectrophotometer, which measures the percentage of light transmitted at
specific frequencies so that the molarity of a sample can be determined without
doing a titration
Computer-assisted labs that use probes to take readings, e.g., temperature
and pressure, so that programs available for computers can print out a graph of
the relationship of readings taken over time