Question

Calculate ?G (in kJ) at 65 oC for the reaction:

N2O(0.0086 atm) + H2(0.55 atm) ? N2(736.6 atm) +H2O(l)

Calculate the vapor pressure of Hg at 75 oC (in atm).

Hg(l) ? Hg(g) . . . ?Ho = 61.32 kJ and ?So = 98.83 J/K

Answer 1

Ans 1

N2O + H2 = N2 + H2O

pressure equilibrium constant expression for the reaction

Kp = [P(N2)] /[P(N2O)*P(H2)]

= (736.6 atm)/((0.0086 atm)*(0.55 atm))

Kp = 1.557 x 10^5 atm-1

Kp = Kc(RT)^n

Kp = 1.557 x 10^5 atm-1
n = (moles products) - (moles reactants)

= 2 - 2

= 0
R = 0.082057 L-atm/mol-K
T = 65 + 273.15 = 338.15 K

Kp = Kc(RT)^n
Kc = Kp/(RT^0)
Kc = (1.557 x 10^5 atm-1)
G = -RT*ln(Kc)

G = -(0.008314 kJ mol^-1 K^-1.)*(338.15 K)*(ln 1.557 x 10^5)
G = -33.62 kJ mol^-1