For the reaction: 2CH3OH(l) + 3O2(g) 2CO2(g) + 4H2O(l) ; H = -1453.2 kJ and S =

Question

For the reaction: 2CH3OH(l) + 3O2(g) 2CO2(g) + 4H2O(l) ; H = -1453.2 kJ and S = -162 J/K at 25oC Calculate G A. -1404.9 kJ B. 1404.9 kJ C. 1.4049 kJ For the reaction A(g) + 2B(g) C(g) ; Kc = 10 Which direction will it proceed if [A] = 0.100, [B]= 0.100 , and [C] = 0.100 is found before equilibrium is established? A. right B. no change C. left For the system: 2NO2(g) N2O4(g) H = -14 kcal ; increasing the temperature will shift the equilibrium: A. left B. right C. no change For the system: H2(g) + Cl2(g) 2HCl(g) ; Go = -190.6 kJ at 25oC. Calculate the equilibrium constant. (be careful of the negative sign) A. 0.0023 B. 2.6 x 1033 C. 3.9 x 10-34

Explanation / Answer

1)

we know that

dG = dH-TdS

given

dH = -1453.2 x 1000 J

dS = -162 J/K

temperature (T) = 25 C = 25 + 273 K = 298 K

so

using those values

we get

dG = (-1453.2 x 1000) - ( 298 x -162)

dG = -1404.924 x 1000

dG = -1404.924 kJ

so

the answer is A) -1404.9 kJ

2)

consider the given reaction

A + 2 B ---> C

the reaction quotient is given by

Q = [C] / [A] [B]^2

using given values

Q = [0.1] / [0.1] [0.1]^2

Q = 100

we know that

if Q < Kc , the reaction will proceed towards right , products

if Q = Kc , no change

if Q > Kc , the reaction will proceed towards left , reactants

in this case

Q = 100 > Kc = 10

so

the reaction will proceed towards left

so

the answer is C) left

3)

given

dH = -14 kcal

so heat is released by the equation

so

the equation can be written as

2N02 ---> N204 + heat

now

we know that

according to Le Chatlier principle

the equilibrium will shift in a direction to counter the change

given temperature is increased, that is heat is added

so

to decreased the temperature or to decrease the heat , the equilibrium will shift towards the reactants where there is no heat .

so

the equilibrium will shift to the left , reactants

the answer is A) left

4)

we know that

dGo = -RT lnK

given

temperature (T) = 298 K

so

-190.6 x 1000 = -8.314 x 298 x lnK

K = 2.57 x 10^33

so

the answer is B) 2.6 x 10^33

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.