JEE Main 2020 Question Paper (04-Sep-2020) (Shift 2)

Question 1

The reaction in which the hybridisation of the underlined atom is affected is

Accepted Answer

$ \overline{X}\mathrm{eF}_4 + \mathrm{SbF}_5 	o $

Answer

$ \mathrm{H_3}\overline{\mathrm{P}}\mathrm{O_2} \xrightarrow{	ext{Disproportionation}} $

Answer

$ \mathrm{H}_2\mathrm{SO}_4 + \mathrm{NaCl} \xrightarrow{420\,\mathrm{K}} $

Answer

$\overline{	ext{NH}}_3 \xrightarrow{	ext{H}^+}$

Question 2

$250\ \mathrm{mL}$ of a waste solution obtained from the workshop of a goldsmith contains $0.1\ \mathrm{M}\ \mathrm{AgNO}_3$ and $0.1\ \mathrm{M}\ \mathrm{AuCl}$. The solution was electrolyzed at $2\ \mathrm{V}$ by passing a current of $1\ \mathrm{A}$ for $15$ minutes. The metal/metals electrodeposited will be: $\left(E_{\mathrm{Ag}^+/\mathrm{Ag}}^0 = 0.80\, \mathrm{V},\ E_{\mathrm{Au}^+/\mathrm{Au}}^0 = 1.69\, \mathrm{V}\right)$

Accepted Answer

only gold

Answer

silver and gold in proportion to their atomic weights

Answer

only silver

Answer

silver and gold in equal mass proportion

Question 3

An alkaline earth metal $\mathrm{M}$ readily forms water soluble sulphate and water insoluble hydroxide. Its oxide $\mathrm{MO}$ is very stable to heat and does not have rock-salt structure. $\mathrm{M}$ is

Accepted Answer

$ \mathrm{Be} $

Answer

$ \mathrm{Sr} $

Answer

$ \mathrm{Ca} $

Answer

$\mathrm{Mg}$

Question 4

The incorrect statement(s) among (a) - (c) is (are): (a) $\mathrm{W}\left(\mathrm{VI}\right)$ is more stable than $\mathrm{Cr}\left(\mathrm{VI}\right)$. (b) In the presence of $\mathrm{HCl}$, permanganate titrations provide satisfactory results. (c) Some lanthanoid oxides can be used as phosphors.

Accepted Answer

(b) only

Answer

(b) and (c) only

Answer

(a) and (b) only

Answer

(a) only

Question 5

The shortest wavelength of $\mathrm{H}$ atom in the Lyman series is ${\lambda}_{1}$. The longest wavelength in the Balmer series of ${\mathrm{He}}^{+}$ is :

Accepted Answer

$\frac{9 \lambda_{1}}{5}$

Answer

$\frac{36 \lambda_{1}}{5}$

Answer

$\frac{5 \lambda_{1}}{9}$

Answer

$\frac{27 \lambda_{1}}{5}$