Consider the cell at 25$$^\circ$$C

Zn | Zn²⁺ (aq), (1M) || Fe³⁺ (aq), Fe²⁺ (aq) | Pt(s)

The fraction of total iron present as Fe³⁺ ion at the cell potential of 1.500 V is x $$\times$$ 10^$$-$$2. The value of x is ______________. (Nearest integer)

(Given : $$E_{F{e^{3 + }}/F{e^{2 + }}}^0 = 0.77V$$, $$E_{Z{n^{2 + }}/Zn}^0 = - 0.76V$$)

At 298 K, the enthalpy of fusion of a solid (X) is 2.8 kJ mol^$$-$$1 and the enthalpy of vaporisation of the liquid (X) is 98.2 kJ mol^$$-$$1. The enthalpy of sublimation of the substance (X) in kJ mol^$$-$$1 is _____________. (in nearest integer)

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)

Consider the complete combustion of butane, the amount of butane utilized to produce 72.0 g of water is ___________ $$\times$$ 10^$$-$$1 g. (in nearest integer)