Page 28 - Basic physical chemistry for the atmospheric sciences

1 4 Basic physical chemistry

COO(s) + CO(g) � CO(s) + C02(g)
are 67 and 490, respectively. What is the equilibrium con­
stant at 823K for the following reaction?
C02(g) + H2(g) � CO(g) + H20(g)

1 . 1 7 . If the equilibrium constant KP for the reaction
N H 4Cl(s) � NH3(g) + HCl(g)
2
s
is 4 x 10- atm at a temperature T, what will be the equilib­
rium vapor pressures of NH3(g) and HCl(g) produced by the
decomposition of NH4Cl(s) at temperature T?
1 . 1 8 . At the high temperatures at which exhaust gases are emitted
from automobiles, the reaction

13
has an equilibrium constant K P of about l x 10- atm. If
the percentages by volume of the exhaust gases at l atm are
.
0 3 0 of O (g), 13 of C0 (g), and 4 . 0 of 02(g), what is the
C
2
reaction quotient for the above reaction? As the reaction
moves to equilibrium, what gases will be produced?
l. 1 9 . B y applying the concepts of chemical equilibrium constants
to the physical equilibrium between liquid water and water
vapor

show that the equilibrium vapor pressure of water is given
by

PH o=[Hz O(g)] R�T
2
where [H20(g)] is the concentration in molarity of the
H 2 0(g). (Note that this relation is a form of the ideal gas
equation.)
1 . 20. If Reaction (c) given in Exercise 1 . 8 is at equilibrium, what
will be the effect on the amount of water vapor of decreasing
the volume of the system at constant temperature?
l . 2 1 . If in the reaction
N204(g) �2N02(g)

a fraction f of the original concentration of N204(g) has
dissociated when equilibrium is reached, derive an expres-