NTA JEE Main 24th February 2021 Shift 2 - Chemistry

According to Bohr's atomic theory:
(A) Kinetic energy of electron is $$\propto \frac{Z^2}{n^2}$$.
(B) The product of velocity (v) of electron and principal quantum number (n), $$'vn' \propto Z^2$$.
(C) Frequency of revolution of electron in an orbit is $$\propto \frac{Z^3}{n^3}$$.
(D) Coulombic force of attraction on the electron is $$\propto \frac{Z^3}{n^4}$$.
Choose the most appropriate answer from the options given below:

The correct set from the following in which both pairs are in correct order of melting point is:

The correct shape and I - I - I bond angles respectively in $$I_3^-$$ ion are:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Hydrogen is the most abundant element in the Universe, but it is not the most abundant gas in the troposphere.
Reason R: Hydrogen is the lightest element.
In the light of the above statements, choose the correct answer from the options given below:

Match List - I with List - II.

Which one of the following compounds is non-aromatic?

What is the correct sequence of reagents used for converting nitrobenzene into m-dibromobenzene?

The correct order of the following compounds showing increasing tendency towards nucleophilic substitution reaction is:

Given below are two statements:
Statement I: The value of the parameter "Biochemical Oxygen Demand (BOD)" is important for survival of aquatic life.
Statement II: The optimum value of BOD is 6.5 ppm.
In the light of the above statements, choose the most appropriate answer from the options given below:

Most suitable salt which can be used for efficient clotting of blood will be?

Match List - I with List - II.

The incorrect statement among the following is:

What is the correct order of the following elements with respect to their density?

The calculated magnetic moments (spin only value) for species $$[FeCl_4]^{2-}$$, $$[Co(C_2O_4)_3]^{3-}$$ and $$MnO_4^{2-}$$ respectively are:

Which of the following reagent is suitable for the preparation of the product in the above reaction?

Which one of the following carbonyl compounds cannot be prepared by addition of water on an alkyne in the presence of $$HgSO_4$$ and $$H_2SO_4$$?

The diazonium salt of which of the following compounds will form a coloured dye on reaction with $$\beta$$-Naphthol in NaOH?

Match List - I with List - II.

Choose the correct answer from the options given below:

In polymer Buna-S, 'S' stands for:

Match List - I with List - II.

The formula of a gaseous hydrocarbon which requires 6 times of its own volume of $$O_2$$ for complete oxidation and produces 4 times its own volume of $$CO_2$$ is $$C_xH_y$$. The value of y is ______.

1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of acetanilide obtained after purification (in g) is ______ $$\times 10^{-2}$$.

The volume occupied by 4.75 g of acetylene gas at 50°C and 740 mm Hg pressure is ______ L.
(Rounded off to the nearest integer)
[Given R = 0.0826 L atm K$$^{-1}$$ mol$$^{-1}$$]

Assuming ideal behaviour, the magnitude of log K for the following reaction at 25°C is $$x \times 10^{-1}$$. The value of x is ______. (Integer answer)
$$3HC \equiv CH_{(g)} \rightleftharpoons C_6H_{6(l)}$$
[Given: $$\Delta_f G^{\circ}(HC \equiv CH) = -2.04 \times 10^5$$ J mol$$^{-1}$$; $$\Delta_f G^{\circ}(C_6H_6) = -1.24 \times 10^5$$ J mol$$^{-1}$$; R = 8.314 J K$$^{-1}$$ mol$$^{-1}$$]

The solubility product of $$PbI_2$$ is $$8.0 \times 10^{-9}$$. The solubility of lead iodide in 0.1 molar solution of lead nitrate is $$x \times 10^{-6}$$ mol/L. The value of x is ______ (Rounded off to the nearest integer)
[Given $$\sqrt{2} = 1.41$$]

$$C_6H_6$$ freezes at 5.5°C. The temperature at which a solution of 10 g of $$C_4H_{10}$$ in 200 g of $$C_6H_6$$ freeze is ______ °C. (nearest integer value), (The molal freezing point depression constant of $$C_6H_6$$ is 5.12°C/m.)

The magnitude of the change in oxidising power of the $$MnO_4^- / Mn^{2+}$$ couple is $$x \times 10^{-4}$$ V if the $$H^+$$ concentration is decreased from 1 M to $$10^{-4}$$ M at 25°C. (Assume concentration of $$MnO_4^-$$ and $$Mn^{2+}$$ to be same on change in $$H^+$$ concentration). The value of x is ______. (Rounded off to the nearest integer)
[Given: $$\frac{2.303RT}{F} = 0.059$$]

Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of 3.33 h at 25°C. After 9 h, the fraction of sucrose remaining is f. The value of $$\log_{10}\left(\frac{1}{f}\right)$$ is ______ $$\times 10^{-2}$$.
(Rounded off to the nearest integer)
[Assume: ln10 = 2.303, ln 2 = 0.693]

Among the following allotropic forms of sulphur, the number of allotropic forms, which will show paramagnetism is ______.
(A) $$\alpha$$-sulphur
(B) $$\beta$$-sulphur
(C) $$S_2$$-form

The total number of amines among the following which can be synthesized by Gabriel synthesis is ______.