A paper dipped in a dil. $\mathrm{H}_2 \mathrm{SO}_4$ solution of ' $X$ ' upon treatment with $\mathrm{SO}_2$ gas turns into green. The compound ' $X$ ' is :

The total number of unpaired electrons present in the $d^3, d^4$ (low spin) $d^5$ (high spin), $\mathrm{d}^6$ (high spin) and $\mathrm{d}^7$ (low spin) octahedral complex systems is $\_\_\_\_$ .

RMgI when treated with ice cold water liberated a gas which occupied $1.4 \mathrm{dm}^3 / \mathrm{g}$ at STP. The gas produced is further reacted with iodine in presence of $\mathrm{HIO}_3$ to give compound $(\mathrm{X})$. Compound $(\mathrm{X})$ in presence of Na and dry ether produced compound $(\mathrm{Y})$. Molar mass of compound $(\mathrm{Y})$ is $\_\_\_\_$ $\mathrm{g} \mathrm{mol}^{-1}$. (Nearest integer)

20 g hemoglobin in a 1 L aqueous solution $(\mathrm{A})$ at 300 K is separated from pure water by semi permeable membrane. At equilibrium the height of solution in a tube dipped in a solution (A) is found to be 80.0 mm higher than the tube dipped in water.

The molar mass of hemoglobin is $\_\_\_\_$ $\mathrm{kg} \mathrm{mol}^{-1}$. (Nearest integer)

(Given : $\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}, \mathrm{R}=8.3 \mathrm{kPa} \mathrm{dm} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$, density of solution $=1000 \mathrm{~kg} \mathrm{~m}^{-3}$ )