JEE (Advanced) 2021 Paper-2
For the following questions answer them individually
For the following reaction
the rate of reaction is $$\frac{d[P]}{dt} = k[X]$$. Two moles of X are mixed with one mole of Y to make 1.0 L of solution. At 50 s, 0.5 mole of Y is left in the reaction mixture. The correct statement(s) about the reaction is(are)
(Use: ln 2 = 0.693)
Some standard electrode potentials at 298 K are given below:
Pb$$^{2+}$$/Pb -0.13 V
Ni$$^{2+}$$/Ni -0.24 V
Cd$$^{2+}$$/Cd -0.40 V
Fe$$^{2+}$$/Fe -0.44 V
To a solution containing 0.001 M of X$$^{2+}$$ and 0.1 M of Y$$^{2+}$$, the metal rods X and Y are inserted (at 298 K) and connected by a conducting wire. This resulted in dissolution of X. The correct combination(s) of X and Y, respectively, is(are)
(Given: Gas constant, R = 8.314 J K$$^{-1}$$ mol$$^{-1}$$, Faraday constant, F = 96500 C mol$$^{-1}$$)
The pair(s) of complexes wherein both exhibit tetrahedral geometry is(are)
(Note: py = pyridine
Given: Atomic numbers of Fe, Co, Ni and Cu are 26, 27, 28 and 29, respectively)
Question Stem
At 298 K, the limiting molar conductivity of a weak monobasic acid is $$4 \times 10^2 S cm^2 mol^{-1}$$. At 298 K, for an aqueous solution of the acid the degree of dissociation is $$\alpha$$ and the molar conductivity is $$๐ฒ \times 10^2 S cm^2 mol^{-1}$$. At 298 K, upon 20 times dilution with water, the molar conductivity of the solution becomes $$3๐ฒ \times 10^2 S cm^2 mol^{-1}$$.
Question Stem
Reaction of x g of Sn with HCl quantitatively produced a salt. Entire amount of the salt reacted with y g of nitrobenzene in the presence of required amount of HCl to produce 1.29 g of an organic salt (quantitatively).
(Use Molar masses (in g mol$$^{-1}$$) of H, C, N, O, Cl and Sn as 1, 12, 14, 16, 35 and 119, respectively).
Question Stem
A sample (5.6 g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 mL of solution. Titration of 25.0 mL of this solution requires 12.5 mL of 0.03 M $$KMnO_4$$ solution to reach the end point. Number of moles of Fe$$^{2+}$$ present in 250 mL solution is $$x \times 10^{โ2}$$ (consider complete dissolution of $$FeCl_2$$). The amount of iron present in the sample is y% by weight.
(Assume: $$KMnO_4$$ reacts only with Fe$$^{2+}$$ in the solution
Use: Molar mass of iron as 56 g mol$$^{โ1}$$)
