NTA JEE Main 25th January 2023 Shift 1

The total number of lone pairs of electrons on oxygen atoms of ozone is

A litre of buffer solution contains 0.1 mole of each of NH$$_3$$ and NH$$_4$$Cl. On the addition of 0.02 mole of HCl by dissolving gaseous HCl, the pH of the solution is found to be _____ $$\times 10^{-3}$$ (Nearest integer)
Given: pK$$_b$$(NH$$_3$$) = 4.745
log 2 = 0.301
log 3 = 0.477
T = 298 K

The density of a monobasic strong acid (Molar mass 24.2 g mol) is 1.21 kg L. The volume of its solution required for the complete neutralization of 25 mL of 0.24 M NaOH is $$10^{-2}$$ mL (Nearest integer)

In sulphur estimation. 0.471 g of an organic compound gave 1.4439 g of barium sulphate. The percentage of sulphur in the compound is _____ (Nearest Integer)
(Given: Atomic mass Ba: 137u, S: 32u, O: 16u)

The osmotic pressure of solutions of PVC in cyclohexanone at 300 K are plotted on the graph. The molar mass of PVC is _____ g mol$$^{-1}$$ (Nearest integer)

(Given: R = 0.083 L atm K$$^{-1}$$ mol$$^{-1}$$)

Consider the cell Pt(s)|H$$_2$$(s)(1atm)|H$$^+$$(aq, [H$$^+$$] = 1)||Fe$$^{3+}$$(aq), Fe$$^{2+}$$(aq)|Pt(s)
Given: E$$_{Fe^{3+}/Fe^{2+}}^\circ$$ = 0.771 V and E$$_{H^+/\frac{1}{2}H_2}^\circ$$ = 0 V, T = 298 K
If the potential of the cell is 0.712 V the ratio of concentration of Fe$$^{2+}$$ to Fe$$^{3+}$$ is _____ (Nearest integer)

For the first order reaction A $$\to$$ B the half life is 30 min. The time taken for 75% completion of the reaction is _____ min. (Nearest integer)
Given: log 2 = 0.3010
log 3 = 0.4771
log 5 = 0.6989

The number of paramagnetic species from the following is
[Ni(CN)$$_4$$]$$^{2-}$$, [Ni(CO)$$_4$$], [NiCl$$_4$$]$$^{2-}$$
[Fe(CN)$$_6$$]$$^{4-}$$, [Cu(NH$$_3$$)$$_4$$]$$^{2+}$$
[Fe(CN)$$_6$$]$$^{3-}$$ and [Fe(H$$_2$$O)$$_6$$]$$^{2+}$$

How many of the following metal ions have similar value of spin only magnetic moment in gaseous state?
(Given: Atomic number: V, 23; Cr, 24; Fe, 26; Ni, 28)
V$$^{3+}$$, Cr$$^{3+}$$, Fe$$^{2+}$$, Ni$$^{3+}$$

An athlete is given 100 g of glucose (C$$_6$$H$$_{12}$$O$$_6$$) for energy. This is equivalent to 1800 kJ of energy. The 50% of this energy gained is utilized by the athlete for sports activities at the event. In order to avoid storage of energy, the weight of extra water he would need to perspire is _____ g (Nearest integer) Assume that there is no other way of consuming stored energy.
Given: The enthalpy of evaporation of water is 45 kJ mol$$^{-1}$$
Molar mass of C, H & O are 12.1 and 16 g mol$$^{-1}$$.