2SO₂(g) + O₂(g) $$\to$$ 2SO₃(g)

The above reaction is carried out in a vessel starting with partial pressure P_SO2 = 250 m bar, P_O2 = 750 m bar and P_SO3 = 0 bar. When the reaction is complete, the total pressure in the reaction vessel is _______ m bar. (Round off of the nearest integer).

The density of NaOH solution is 1.2 g cm^$$-$$3. The molality of this solution is _____________ m. (Round off to the Nearest Integer)

[Use : Atomic mass : Na : 23.0 u, O : 16.0 u, H : 1.0 u, Density of H₂O : 1.0 g cm^$$-$$3]

The number of significant figures in 0.00340 is ____________.

When 10 mL of an aqueous solution of Fe²⁺ ions was titrated in the presence of dil H₂SO₄ using diphenylamine indicator, 15 mL of 0.02 M solution of K₂Cr₂O₇ was required to get the end point. The molarity of the solution containing Fe²⁺ ions is x $$\times$$ 10^$$-$$2 M. The value of x is __________. (Nearest integer)