These are physical properties of an element

(A) Sublimation enthalpy

(B) Ionisation enthalpy

(C) Hydration enthalpy

(D) Electron gain enthalpy

The total number of above properties that affect the reduction potential is ____________ (Integer answer)

Of the following four aqueous solutions, total number of those solutions whose freezing point is lower than that of 0.10 M C₂H₅OH is __________ (Integer answer)

(i) 0.10 M Ba₃(PO₄)₂

(ii) 0.10 M Na₂SO₄

(iii) 0.10 M KCl

(iv) 0.10 M Li₃PO₄

The OH^$$-$$ concentration in a mixture of 5.0 mL of 0.0504 M NH₄Cl and 2 mL of 0.0210 M NH₃ solution is x $$\times$$ 10^$$-$$6 M. The value of x is ___________. (Nearest integer)

[Given K_w = 1 $$\times$$ 10^$$-$$14 and K_b = 1.8 $$\times$$ 10^$$-$$5]

The number of 4f electrons in the ground statement electronic configuration of Gd²⁺ is ___________. [Atomic number of Gd = 64]