Download Sec. 12.3: Molecular Composition of Gases 1) Boyle`s Law: a

Sec. 12.3: Molecular Composition of Gases
1) Boyle’s Law:
a) Charles’ Law:
b) Gay-Lussac’s Law:
c) Avogadro’s Law:
2) Ideal gas: an _________________ gas whose particles are infinitely ____________ and
do ____________ interact with each other.
a) An ideal gas:
i) Does _____ condense to a _____________ at ___________ temperatures.
ii) Does not have forces of ______________ or repulsion between the ____________.
iii) Is composed of ______________ that have no ______________.
3) Ideal gas law: the law that states the mathematical relationship of pressure (P), volume
(V), temperature (T), the gas constant (R), and the number of moles of a gas (n).
a) Ideal gas law equation:
4) R is a proportionality constant.
a) For Pressure in kPa, R =
b) For Pressure in atm, R =
5) Real gases _____________ somewhat from an __________ gas and more so at very
_____________ ______________.
6) Sample problem E, pg 435
How many moles of gas are contained in 22.41 liters at 101.325 kPa and 0˚C?
7) Additional Practice
a) What is the volume of 4.35 moles of a gas at a pressure of 85.6 kPa and 26.0˚C?
8) Diffusion: the _________________ of particles from regions of _____________
density to regions of lower ________________.
a) The process of _____________ involves an ______________ in _____________.
9) Effusion: the passage of gas under ______________ through a tiny _____________.
a) Scottish scientist Thomas Graham found that at constant ____________ and
_____________, the rate of effusion of a gas is __________ proportional to the
square root of the gases __________ __________, M.
10) Graham’s law of diffusion equation:
V = velocity (molecular speed) of gas A and B
M = molar mass of gas A and B
a) Particles of __________ molar mass travel __________ than __________ particles.
11) Sample problem F, pg. 438
Oxygen molecules have an average speed of about 480 m/s at room temperature. At the
same temperature, what is the average speed of molecules of sulfur hexafluoride, SF6?
12) Additional Practice
The average velocity of CO2 molecules at room temperature is 409 m/s. What is the molar
mass of a gas whose molecules have an average velocity of 322 m/s under the same
conditions?
13) In 1808, Joseph Gay-Lussac made an important discovery: if the __________ and
______________ are kept constant, gases react in ____________ proportions that are
__________ __________ __________.
a) Gay-Lussac’s law of combining volumes: the law that states that the _____________
of gases involved in a chemical change can be represented by the ____________ of
small whole numbers.
14) Gas reactions allow __________ ____________ to be deduced.
a) Hydrogen molecules combine with __________ molecules in a 1:1 volume ratio to
produce __________ the volume of hydrogen chloride, HCl.
15) In 1805, John Dalton showed that in a ______________ of gases, each gas exerts a
certain ____________ as if it were ______________ with no other gases mixed with it.
a) Partial Pressure: the _____________ of each gas in a ________________.
b) Dalton’s law of partial pressure: the law that states that the ____________
pressure of a mixture of gases is the __________ of the ____________ pressures
of the component gases.
16) Dalton’s law of partial pressures equation:
a) P total = total pressure
b) PA = partial pressure of gas A
c) PB = partial pressure of gas B
d) PC = partial pressure of gas C
17) Dalton’s law of __________ __________ is explained by the ____________
____________ theory.
a) All the gas molecules are moving _____________, and each has an __________ chance
to ____________ with the container wall.
b) Each gas exerts a pressure _______________ to its number of _____________ in
the container. The presence of other gas molecules __________ __________
change this fact.
18) Ratios of gas __________ will be the same as __________ __________ of gases in
_______________ equations.
a) Avogadro’s law shows that the __________ __________ of two gases at the same
temperature and pressure is the same as the _____________ ratio of the two gases.
19) For example:
3 H2 (g) + N2 (g)
2 NH3 (g)
a) 3 L of H2 react with 1 L of N2 to form 2 L of NH3 with no H2 or N2 left over
b) If we know the number of __________ of a gaseous substance, we can use the
__________ __________ __________ to calculate the __________ of that gas.
20) Sample problem G, pg, 441
How many liters of hydrogen gas will be produced at 280.0 K and 96.0 kPa if 1.74 mol of
sodium react with excess water according to the following equation?
2Na (s) + 2 H2O (l)
2 NaOH
(aq)
+ H2 (g)
21) Additional Practice
A student wished to prepare oxygen by using the thermal decomposition of potassium
chlorate, KClO3. Given that the gas will have a temperature of 700˚C and a pressure of 98.6
kPa, how much potassium chlorate will be necessary to produce 125 mL of oxygen?
Δ
2 KClO3
3 O2 + 2 KCl
22)
Methane has a volume of 0.65 L when under 100 kPa of pressure at a temperature of
305 K. Using the balanced equation below, find the mass of oxygen that is needed to use
up all of the methane.
CH4 + 2 O2
CO2 + 2 H2O