Given below are two statements :

Statement (I) : The radii of isoelectronic species increases in the order.

Mg²⁺ < Na⁺ < F^$-$ < O^2-

Statement (II) : The magnitude of electron gain enthalpy of halogen decreases in the order.

Cl > F > Br > I

In the light of the above statements, choose the most appropriate answer from the options given below :

The molar mass of the water insoluble product formed from the fusion of chromite ore (FeCr₂O₄) with Na₂CO₃ in presence of O₂ is ___________ g mol^⁻¹.

Given below are some nitrogen containing compounds :

Each of them is treated with HCl separately. 1.0 g of the most basic compound will consume _______ mg of HCl.

(Given molar mass in g mol⁻¹ C : 12, H : 1, O : 16, Cl : 35.5)

If A₂B is 30% ionised in an aqueous solution, then the value of van't Hoff factor (i) is _______ × 10⁻¹.