Video Transcript
Which of the following is not a
major use of ethanol? (A) Thermometers, (B) industrial
solvent, (C) antiseptic, (D) packaging, or (E) fuel.
Ethanol is one of the smallest and
simplest alcohol molecules, and manufacturers use it for lots of different
purposes. The compound has the chemical
formula C2H5OH, and it is polar because it has a single hydroxy group. Let us recall that ethanol can
undergo a combustion reaction. We can also recall that it destroys
different pathogenic microbes because of its chemical properties. We might also remember that it is a
widely used industrial solvent because it is an easy to manufacture polar
solvent.
Let us use some of the information
in this video to start discounting the incorrect answer options. We know that option (B) is not
correct as we just stated that manufacturers use ethanol as an industrial
solvent. The compound has a single OH group,
and this makes it polar. Ethanol can dissolve other polar
molecules because it has an asymmetrical distribution of electron density.
We can similarly figure out that
choice (C) is incorrect because we stated that ethanol kills pathogenic
microbes. Lots of antiseptic wipes destroy
pathogenic bacteria because they contain ethanol or some other alcohol molecule. We can infer that choice (E) is
incorrect since ethanol undergoes a complete combustion reaction at a high
temperature.
Some people use ethanol fuel to
power vehicles, and others blend it with low-octane-number fuels. Ethanol has a relatively
high-octane rating and can help other fuels reach minimum octane number
requirements.
We can see that the answer is
either choice (A) or (D). We should remember that some
thermometers contain ethanol rather than mercury. Ethanol is preferred over mercury
partly because it is less toxic. We see that option (A) is correct,
and so option (D) must be the answer.
Ethanol is a liquid at room
temperature and is not suitable as packaging for other materials. Of the answer choices given, the
one that is not a major use of ethanol is (D), packaging.
