2. The Atmosphere
mixture of gases surrounding the Earth
vast number of reactions both desirable and
undesirable happens mostly driven by energy
from solar photons
has a total mass (atmosphere) of 5.3 X 10 15
metric tons
11. Kinetic Molecular Theory
A gas is composed of
molecules whose size
is much smaller than
the distances
between them.
Gas molecules move
randomly at various
speeds and in every
possible direction.
12. Kinetic Molecular Theory
Except when gas
molecules collide,
forces of attraction and
repulsion between
them are negligible.
When collisions between
molecules occur, the
collision are elastic.
13. Kinetic Molecular Theory
The average kinetic
energy of gas
molecules is
proportional to the
absolute temperature.
17. Sample Problems on Boyle’s Law
A gas sample occupies a volume
of 100 mL at a pressure of 0.4
atm. What volume will the gas
occupy if pressure is increased
to 1.5 atm? Assume
temperature is kept constant.
A gas occupies a volume of 458 mL at
a pressure of 1.10kPa and a
temperature of 295 K. When the
pressure is changed, the volume
becomes 471 mL. If there has been
no change in the temperature, what
is the new pressure?
