The equilibrium constant Kc at 298 K for the reaction A + B ⥨ C + D is 100. Starting with an equimolar solution with concentration of A, B, C and D all equal to 1 M, the equilibrium concentration of D is ___________________ × 10⁻² M. (Nearest integer)

When starting with equimolar concentrations (1M each) and given Kc=100,

we need to solve for the equilibrium shift.

If x is the amount reacted, then at equilibrium: [A]=[B]=1-x, [C]=[D]=1+x.

Substituting into Kc expression:

Kc = ([C][D])/([A][B]) = ((1+x)(1+x))/((1-x)(1-x)) = (1+x)²/(1-x)² = 100.

Taking square root: (1+x)/(1-x) = 10. Solving for x: x = 0.818.

Therefore [D] = 1 + 0.818 = 1.818 M = 182 × 10⁻² M.