Predicting Reaction Direction and Calculating Equilibrium Concentrations roblem

Question

Predicting Reaction Direction and Calculating Equilibrium Concentrations roblem 4 PROBLEM: The research and development unit of a chemical company is studying the reaction of CH4 and H2S, two components of natural gas CH4(g) + 2H,s(g) CS2(g) + 4H2(g) In one experiment, 1.00 mol of CH4 1.00 mol of CS2, 2.00 mol of H2S, and 2.00 mol of H2 are mixed in a 250-mL vessel at 960°C. At this temperature, Kc = 0.036. (a) In which direction will the reaction proceed to reach equilibrium? (b) If [CH4] = 5.56 M at equilibrium, what are the equilibrium concentrations of the other substances?

Explanation / Answer

CH4(g) + 2H2S(g) <===> CS2(g) + 4 H2(g)

kC = [H2]^4[CS2]/[H2S]^2[CH4]

at given conditions,

Qc = [H2]^4[CS2]/[H2S]^2[CH4]

     = (2/0.25)^4*(1/0.25)/((2/0.25)^2*(1/0.25))

     = 64

Qc > Kc. so that backward reaction is favourable (products converts into reactants)

at equilibrium

               CH4(g)    +    2H2S(g) <===> CS2(g) + 4 H2(g)

at equil 1/0.25 = 4+x        8+2x           4-x      8-4x

we know that,

[CH4] = 4+x = 5.56 M

      x = 1.56

[H2S] = 8+2*1.56 = 11.12 M

[cs2] = 4-1.56 = 2.44 M

[H2] = 8-4*1.56 = 1.76 M

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---