23) Assume the reaction A + B C + D proceeds to equilibrium. Calculate the equil

Question

23) Assume the reaction A + B C + D proceeds to equilibrium. Calculate the equilibrium concentration of D at 25°C, given that the starting concentrations of A and B are 2M and that Go for the reaction is 1.0 kcal/mol. R= 1.987 cal/mol. K. A) 0.40M B) 0.60M C) 1.00M D) 1.40M E) 1.60M Answer: B Diff: 3 Section: 4.4 24) Consider the following substitution reaction with a G° value of-91.1 kJ/mole. HO-+ CH3Cl CH3OH + Cl- Given this information which of the following statements must be true? (R 8.315 J/mole K) A) The Ke q at 25°C for this reaction is very large, in other words this reaction proceeds to near nlation as written, left to right under standard conditions

Explanation / Answer

   DG^0 = -RTlnK
DG^0 = 1KCal/mol   = 1000cal/mol
T     = 25+273     = 298K
1000 = -1.987*298*2.303logKc
1000 = -1363.66logKc
logKc = -1000/1363.66
logKc   = -0.73
    Kc   = 10^-0.73   = 0.186
   A + B --------> C + D
I 2    2           0   0
C -x    -x          + x +x
E 2-x   2-x         +x   +x

    Kc = [C][D]/[A][B]
    0.186 = x*x/(2-x)(2-x)
    0.186 = (x/2-x)^2
     0.43   = x/2-x
     0.43*(2-x) = x
         x= 0.6
       [D] = x= 0.6M
   

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

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