A 2.0 g sample containing MnO₂ is treated with HCl liberating Cl₂. The Cl₂ gas is passed into a solution of KI and 60.0 mL of 0.1 M Na₂S₂O₃ is required to titrate the liberated iodine. The percentage of MnO₂ in the sample is _____________. (Nearest integer)

[Atomic masses (in u) Mn = 55; Cl = 35.5; O = 16, I = 127, Na = 23, K = 39, S = 32]

The oxidation number of iron in the compound formed during brown ring test for NO$_3^-$ iron is ________.

Ionic radii of cation $\mathrm{A}^{+}$ and anion $\mathrm{B}^{-}$ are 102 and respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for . is present in all octahedral voids. The edge length of the unit cell of the crystal AB is __________ pm. (Nearest Integer)

The osmotic pressure exerted by a solution prepared by dissolving 2.0 g of protein of molar mass 60 kg mol^$-$1 in 200 mL of water at 27$^\circ$C is ______________ Pa. [integer value]

(use R = 0.083 L bar mol K)

In a solid AB, A atoms are in ccp arrangement and B atoms occupy all the octahedral sites. If two atoms from the opposite faces are removed, then the resultant stoichiometry of the compound is A_xB_y. The value of x is ____________. [nearest integer]

Number of moles of $\mathrm{H}^{+}$ ions required by $1 \mathrm{~mole}$ of to oxidise oxalate ion to is _________.

Atoms of element X form hcp lattice and those of element Y occupy ${2 \over 3}$ of its tetrahedral voids. The percentage of element X in the lattice is ____________. (Nearest integer)