CHEM 123: GENERAL
CHEMISTRY I
DR J - DAY 1
What do chemists do?
-
they synthesize new molecules
that never existed before or discover a preexisting one in nature that we can
use for our own purposes
-
purify the newly synthesized molecules
or preexisting one from other molecules present in the reaction mixture or
in a natural mixture
-
analyze the
structure/composition/properties of the purified molecule
In the first lab you will synthesize
Aspirin and in the second lab you will analyze it!
For today, let's consider purifying a
substance from a mixture. Consider the following examples and associated questions.
- Cu wire in water:
+
- Question -
Does Cu dissolve in water
- Question -
How could you separate Cu and water?
- Question -
What is Cu made of? Take piece and cut it (physical
reaction) in 1/2, the 1/2 in 1/2, and continue with
nanoscopic scissors. At what point can you make no further cuts if
you still want the smallest "particle" to be Cu?
- Take solid water and do the same "cutting"
experiment.
- Question -
What is water made of? At what point can you make no
further cuts if you still want the smallest "particle" to be water? Is
there a way to separate water into something other than water by chemical
reactions?
3. Other simple mixtures:
- Solid in water:
Question - How would your separate the components of these
mixture? sodium chloride and water? sucrose and water? Diamond and water?
- Liquid in water: Question - How would your separate
the components of these mixture? ethanol and water?
gasoline and water?
4. How about some complex mixtures?
- Sea water: Question
- What's in 1 ml of sea water?
- Human body: There are lots of different types
of cells in the human body.
Question - Name some different types of cells the comprise the human body?
What type of cell is most abundant
- Blood: a "simpler mixture" Question -
What 's in blood? How would you separate the components?
