Saved Bookmarks
| 1. |
Derive the value of equilibrium constants K_p and K_c for a general reaction xA + y B hArr lC +mD |
|
Answer» SOLUTION :Let us consider a reversible reaction `xA + YB hArr lC + m D` where, A, B are the reactants C and D are the product and x, y l and m are the stoichiometic coefficients of A, B, C and D respectively. Applying the law of mass action the RATE of forward reaction. `r_f prop[A]^(x)[B]^(y)or r_f[A]^(x)[B]^(y)` Similarly the rate of backward reaction `r_b prop [C]^l [D]^m or r_b = K_b [ C]^l[D]^m` where `K_f` and `K_b` are PROPORTIONALITY constants. At equilibrium . Rate of forward reaction `(r_f)` = Rate of backward reactoin `(r_b)` `thereforeK_(f)[A]^(x). [B]^(y) = K_b[C]^(l) [D]^m` or `(K_f)/(K_b) = ([C]^l [D]^m)/([A]^l. [B]^y)=K_C` where `K_C` is the equilibrium constant in terms of concentration. At a given temperature, the ratio of the product of active masses of reaction products raised. to the respective STOICHIOMETRIC coefficients in the balanced chemical equation to that of the reactants is a constant known as equilibrium constant. If the reactants and products of the above reaction are in gas phase, then the equilibrium constant can be written in terms of partial pressures. `K_p = (p_c^(i) xx p_D^m)/(p_A^x xx p_B^y)` where `P_(A),P_(B),P_(C) " and " P_D` are the partial pressure of gases A,B,C and D respectively. |
|