The equilibrium constant K_c at 298 K for the reaction A + B $$\rightleftharpoons$$ C + D is 100. Starting with an equimolar solution with concentrations of A, B, C and D all equal to 1M, the equilibrium concentration of D is ___________ $$\times$$ 10^$$-$$2 M. (Nearest integer)

The reaction rate for the reaction

[PtCl₄]^2$$-$$ + H₂O $$\rightleftharpoons$$ [Pt(H₂O)Cl₃]^$$-$$ + Cl^$$-$$

was measured as a function of concentrations of different species. It was observed that $${{ - d\left[ {{{\left[ {PtC{l_4}} \right]}^{2 - }}} \right]} \over {dt}} = 4.8 \times {10^{ - 5}}\left[ {{{\left[ {PtC{l_4}} \right]}^{2 - }}} \right] - 2.4 \times {10^{ - 3}}\left[ {{{\left[ {Pt({H_2}O)C{l_3}} \right]}^ - }} \right]\left[ {C{l^ - }} \right]$$.

where square brackets are used to denote molar concentrations. The equilibrium constant K_c = ____________ . (Nearest integer)

The OH^$$-$$ concentration in a mixture of 5.0 mL of 0.0504 M NH₄Cl and 2 mL of 0.0210 M NH₃ solution is x $$\times$$ 10^$$-$$6 M. The value of x is ___________. (Nearest integer)

[Given K_w = 1 $$\times$$ 10^$$-$$14 and K_b = 1.8 $$\times$$ 10^$$-$$5]

The equilibrium constant for the reaction

A(s) $$\rightleftharpoons$$ M(s) + $${1 \over 2}$$O₂(g)

is K_p = 4. At equilibrium, the partial pressure of O₂ is _________ atm. (Round off to the nearest integer)