For complete combustion of methanol

CH₃OH(I) + $${3 \over 2}$$O₂(g) $$\to$$ CO₂(g) + 2H₂O(I)

the amount of heat produced as measured by bomb calorimeter is 726 kJ mol^$$-$$1 at 27$$^\circ$$C. The enthalpy of combustion for the reaction is $$-$$x kJ mol^$$-$$1, where x is ___________. (Nearest integer)

(Given : R = 8.3 JK^$$-$$1 mol^$$-$$1)

A 0.5 percent solution of potassium chloride was found to freeze at $$-$$0.24$$^\circ$$C. The percentage dissociation of potassium chloride is ______________. (Nearest integer)

(Molal depression constant for water is 1.80 K kg mol^$$-$$1 and molar mass of KCl is 74.6 g mol^$$-$$1)

50 mL of 0.1 M CH₃COOH is being titrated against 0.1 M NaOH. When 25 mL of NaOH has been added, the pH of the solution will be _____________ $$\times$$ 10^$$-$$2. (Nearest integer)

(Given : pK_a (CH₃COOH) = 4.76)

log 2 = 0.30

log 3 = 0.48

log 5 = 0.69

log 7 = 0.84

log 11 = 1.04

A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is ___________ s.

(Given : ln 2 = 0.693)