Sulphurous acid (H₂SO₃) has Ka₁ = 1.7 $$\times$$ 10^$$-$$2 and Ka₂ = 6.4 $$\times$$ 10^$$-$$8. The pH of 0.588 M H₂SO₃ is __________. (Round off to the Nearest Integer).

At 363 K, the vapour pressure of A is 21 kPa and that of B is 18 kPa. One mole of A and 2 moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is ___________ kPa. (Round off to the Nearest Integer).

If y = y(x) is the solution of the differential equation

$${{dy} \over {dx}}$$ + (tan x) y = sin x, $$0 \le x \le {\pi \over 3}$$, with y(0) = 0, then $$y\left( {{\pi \over 4}} \right)$$ equal to :

Let f be a real valued function, defined on R $$-$$ {$$-$$1, 1} and given by

f(x) = 3 log_e $$\left| {{{x - 1} \over {x + 1}}} \right| - {2 \over {x - 1}}$$.

Then in which of the following intervals, function f(x) is increasing?