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NTA JEE Main 25th February 2021 Shift 2 - Chemistry

For the following questions answer them individually

Correct statement about the given chemical reaction is:

The correct sequence of reagents used in the preparation of 4-bromo-2-nitroethylbenzene from benzene is:

Given below are two statements:
Statement I: The pH of rain water is normally ~5.6.
Statement II: If the pH of rain water drops below 5.6, it is called acid rain.
In the light of the above statements, choose the correct answer from the options given below:

Which one of the following statements is FALSE for hydrophilic sols?

Given below are two statements:
Statement I: $$\alpha$$ and $$\beta$$ forms of sulphur can change reversibly between themselves with slow heating or slow cooling.
Statement II: At room temperature the stable crystalline form of sulphur is monoclinic sulphur.
In the light of the above statements, choose the correct answer from the options given below:

In which of the following order the given complex ions are arranged correctly with respect to their decreasing spin only magnetic moment?
(i) $$[FeF_6]^{3-}$$
(ii) $$[Co(NH_3)_6]^{3+}$$
(iii) $$[NiCl_4]^{2-}$$
(iv) $$[Cu(NH_3)_4]^{2+}$$

Given below are two statements:
Statement I: The identification of $$Ni^{2+}$$ is carried out by dimethyl glyoxime in the presence of $$NH_4OH$$.
Statement II: The dimethyl glyoxime is a bidentate neutral ligand.
In the light of the above statements, choose the correct answer from the options given below:

Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization energy of metal A in kJ mol$$^{-1}$$ is ______. (Rounded-off to the nearest integer)
[$$h = 6.63 \times 10^{-34}$$ Js, $$c = 3.00 \times 10^8$$ ms$$^{-1}$$, $$N_A = 6.02 \times 10^{23}$$ mol$$^{-1}$$]

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Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2.1 MPa to 1.3 MPa against at constant external pressure 4.3 MPa. The heat transferred in this process is ______ kJ mol$$^{-1}$$.
(Rounded-off to the nearest integer)
[Use $$R = 8.314$$ J mol$$^{-1}$$ K$$^{-1}$$]

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Consider titration of NaOH solution versus 1.25 M oxalic acid solution. At the end point following burette readings were obtained.
(i) 4.5 mL (ii) 4.5 mL (iii) 4.4 mL (iv) 4.4 mL (v) 4.4 mL
If the volume of oxalic acid taken was 10.0 mL then the molarity of the NaOH solution is ______ M. (Rounded-off to the nearest integer)

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The unit cell of copper corresponds to a face centered cube of edge length 3.596 $$\mathring{A}$$ with one copper atom at each lattice point. The calculated density of copper in kg/m$$^3$$ is ______. [Molar mass of Cu: 63.54 g; Avogadro Number $$= 6.022 \times 10^{23}$$]

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If a compound AB dissociates to the extent of 75% in an aqueous solution, the molality of the solution which shows a 2.5 K rise in the boiling point of the solution is ______ molal. (Rounded-off to the nearest integer)
[$$K_b = 0.52$$ K kg mol$$^{-1}$$].

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Copper reduces $$NO_3^-$$ into NO and $$NO_2$$ depending upon the concentration of $$HNO_3$$ in solution. (Assuming fixed $$[Cu^{2+}]$$ and $$P_{NO} = P_{NO_2}$$), the $$HNO_3$$ concentration at which the thermodynamic tendency for reduction of $$NO_3^-$$ into NO and $$NO_2$$ by copper is same is $$10^x$$ M. The value of $$2x$$ is ______. (Rounded-off to the nearest integer)
[Given, $$E^\circ_{Cu^{2+}/Cu} = 0.34$$ V, $$E^\circ_{NO_3^-/NO} = 0.96$$ V, $$E^\circ_{NO_3^-/NO_2} = 0.79$$ V and at 298 K, $$\frac{RT}{F}(2.303) = 0.059$$]

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The rate constant of a reaction increases by five times on increase in temperature from 27°C to 52°C. The value of activation energy in kJ mol$$^{-1}$$ is ______. (Rounded-off to the nearest integer) [$$R = 8.314$$ J K$$^{-1}$$ mol$$^{-1}$$]

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