| Chapter 5 |
Problems 5,9,13,17,19,21,25,27,29,33,37,41,47,51,59. |
| Chapter 6 |
Problems 3,5,7,11,13,17,21,23,27,29. |
| Chapter 7 |
Problems 3,5,7,9,11,13,15,17,19,21,23. |
- Colorful Pyrotechnic Display
of salts of strontium,
barium, and sodium. The reactions are
exothermic and produce characteristic colors which have their origins
in events taking place at the atomic level.
- (a) strontium nitrate/potassium chlorate/charcoal/sulfur.
- (b) barium nitrate/potassium chlorate/sugar.
- (c) sulfur/charcoal/potassium chlorate/sodium oxylate.
- Discharge tubes
filled with different gases
at low pressures also can produce characteristic
colors in the visible when excited. With the aid of a spectroscope,
the sets of lines that are the visual
fingerprints of the gases can be seen. A number of different
gas-filled tubes will be illuminated. Note the characteristic colors:
| Neon | Hydrogen | Helium | Mercury | Argon | Xenon |
- Line spectra
can be observed through a spectroscope
directed at a hydrogen lamp and the
Balmer (visible) series in the bright line spectrum can be
examined
- Nodes and Waves.
With a "Slinky" toy and a
long spring, certain wave properties can be
described, particularly harmonic motion, wave length, and "nodes."
Standing waves of different
wavelengths can be generated.
- . Laser light.
Using a packet-sized laser pointer, and a
silk scarf, diffraction can be illustrated
along with certain other properties of laser light.
- Diamagnetism and
paramagnetism.
Liquid
nitrogen and liquid oxygen are tested for their
magnetic properties by bringing them in close proximity to a powerful
magnet and observing the effects. Since the boiling point of liquid nitrogen is below that of
liquid oxygen, it is possible to use the
former to condense the latter out of the air.
-
Chemiluminescence
, or cold
light, is produced in a complex set of photochemical reactions
involving, among other molecules and ions, an organic substance
called luminol (which responds much as
luciferin does when the firefly sends a glowing message to
prospective mates) and a peroxide oxidizing
agent - in this case, hydrogen peroxide.
- "Light Sticks"
are commercial products
based on chemiluminescence displays. The packaging is
interesting. There is an ampoule within that contains the peroxide.
- Phosphorus Moon
is a luminescent display
involving the burning of phosphorus in an oxygen atmosphere. Burning
elemental (white) phosphorus (P4) in an oxygen atmosphere is
a spontaneous process that produces a characteristic bright yellowish-white glow.
Why does the reaction product produce an acidic response to litmus or phenolphthalein,
in water? Although you can imagine it, or even write chemical equations for the reaction,
the spontaneous combustion reaction is not easily reversible. From thermodynamic data,
available in your textbook, calculate the heat of reaction.
- The Franck-Hertz Experiment.
The characteristic
absorption of mercury vapor in the ultraviolet was used as a key piece of experimental evidence that
helped confirm the Bohr theory of the atom with its "quantized" energy gaps. The actual experimental
demonstration is known as the Franck-Hertz Experiment. In this simpler demonstration, a UV lamp is used
to illuminate a gas mercury vapor.