NTA JEE Main 26th August 2021 Shift 2

100 mL of Na$$_3$$PO$$_4$$ solution contains 3.45 g of sodium. The molarity of the solution is _________ $$\times 10^{-2}$$ mol L$$^{-1}$$. (Nearest integer)
[Atomic Masses - Na : 23.0u, O : 16.0u, P : 31.0u]

For water $$\Delta_{vap}H = 41$$ kJ mol$$^{-1}$$ at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is _________ (kJ mol$$^{-1}$$):
[Use: R = 8.3 J mol$$^{-1}$$ K$$^{-1}$$]

The equilibrium constant $$K_c$$ at 298 K for the reaction A + B $$\rightleftharpoons$$ C + D is 100. Starting with an equimolar solution with concentrations of A, B, C and D all equal to 1M, the equilibrium concentration of D is _________ $$\times 10^{-2}$$ M. (Nearest integer)

In the sulphur estimation, 0.471 g of an organic compound gave 1.44 g of barium sulfate. The percentage of sulphur in the compound is _________ (Nearest integer) (Atomic Mass of Ba = 137u)

The reaction rate for the reaction
$$[PtCl_4]^{2-} + H_2O \rightleftharpoons [Pt(H_2O)Cl_3]^- + Cl^-$$
was measured as a function of concentrations of different species. It was observed that
$$\frac{-d[PtCl_4]^{2-}}{dt} = 4.8 \times 10^{-5}[PtCl_4]^{2-} - 2.4 \times 10^{-3}[Pt(H_2O)Cl_3]^-][Cl^-]$$
where square brackets are used to denote molar concentrations.
The equilibrium constant K$$_c$$ = X (Nearest integer). Value of $$\frac{1}{X}$$ is _________ 
$$K_c = X$$ (Nearest integer)

A chloro compound "A".
(i) forms aldehydes on ozonolysis followed by the hydrolysis.
(ii) when vaporized completely 1.53 g of A, gives 448 mL of vapour at STP. The number of carbon atoms in a molecule of compound A is _________

83 g of ethylene glycol dissolved in 625 g of water. The freezing point of the solution is _________ K. (Nearest integer)
[Use: Molal Freezing point depression constant of water = 1.86 K kg mol$$^{-1}$$
Freezing point of water = 273 K
Atomic masses: C : 12.0u, O : 16.0u, H : 1.0u]

For the galvanic cell,
Zn(s) + Cu$$^{2+}$$(0.02M) $$\rightarrow$$ Zn$$^{2+}$$(0.04M) + Cu(s)
E$$_{cell}$$ = _________ $$\times 10^{-2}$$ V (Nearest integer)
[Use: E$$^0$$ Cu/Cu$$^{2+}$$ = $$-0.34$$ V, E$$_{Zn/Zn^{2+}}$$ = +0.76 V, $$\frac{2.303RT}{F}$$ = 0.059 V]

The overall stability constant of the complex ion $$[Cu(NH_3)_4]^{2+}$$ is $$2.1 \times 10^{13}$$. The overall dissociation constant is $$y \times 10^{-14}$$. Then $$y$$ is _________ (Nearest integer)

A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric current is $$4.3 \times 10^{14}$$ Hz. The velocity of ejected electron is _________ $$\times 10^5$$ ms$$^{-1}$$ (Nearest integer)
[Use: h = $$6.63 \times 10^{-34}$$ Js, m$$_e$$ = $$9.0 \times 10^{-31}$$ kg]