Page 27 - Basic physical chemistry for the atmospheric sciences

Chemical equilibrium

I. I I. What is the value of Kc at 727°C for the reaction given in
Exercise I . I O?
l . I2. If 6. I4 kg of N20ig) equilibrate with 0.062 kg of NOi(g) at
25°C in a 6.00-L vessel, what is the value of Kc for the
following reaction

N20ig) �2NOi(g)
I .13. If 7 .60 g of N20ig) and I .60 g of N02(g) are mixed simulta­
neously within a volume of 3.00 L a t 25°C, what will be the
equilibrium masses of N20 (g) and N02(g) established by
4
the reaction given in Exercise I .12 if the equilibrium con­
stant Kc at 25°C is 4.56 x 10-3?
l. I4. Prove:
(a) The equilibrium constant for a reverse reaction is the
reciprocal of the equilibrium constant for the corres­
ponding forward reaction.
(b) If the coefficients in a balanced chemical equation are
multiplied by a common factor (say m), the new equilib­
rium constant will be the old one raised to the power
of m.
(c) The equilibrium constant for a net reaction is the prod­
uct of the equilibrium constants for the individual reac­
tions that add together to give the net reactio .
n
1.15. Equilibria involving S02(g), 02(g) and S03(g) can be de­
scribed by

(i)
or,

(ii)
or,

(iii)
2
If the equilibrium constant for Reaction (i) is 2.8 x 1 0 at
IOOOK what are the values of the equilibrium constants at
,
lOOOK for Reactions (ii) and (iii)?
1.16. At 823K, the equilibrium constants (K c ) for the reactions
COO(s) + H2(g) � C O(s) + H20(g)

and,