2O₃(g) $$\rightleftharpoons$$ 3O₂(g)

At 300 K, ozone is fifty percent dissociated. The standard free energy change at this temperature and 1 atm pressure is ($$-$$) ____________ J mol^$$-$$1. (Nearest integer)

[Given : ln 1.35 = 0.3 and R = 8.3 J K^$$-$$1 mol^$$-$$1]

When 5.1 g of solid NH₄HS is introduced into a two litre evacuated flask at 27$$^\circ$$C, 20% of the solid decomposes into gaseous ammonia and hydrogen sulphide. The K_p for the reaction at 27$$^\circ$$C is x $$\times$$ 10^$$-$$2. The value of x is _____________. (Integer answer) [Given R = 0.082 L atm K^$$-$$1 mol^$$-$$]

The number of moles of NH₃, that must be added to 2L of 0.80 M AgNO₃ in order to reduce the concentration of Ag⁺ ions to 5.0 $$\times$$ 10^$$-$$8 M (K_formation for [Ag(NH₃)₂]⁺ = 1.0 $$\times$$ 10⁸) is ____________. (Nearest integer)

[Assume no volume change on adding NH₃]

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)