NTA JEE Main 27th August 2021 Shift 1

The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is
$$2K_2Cr_2O_7 + 8H_2SO_4 + 3C_2H_6O \rightarrow 2Cr_2(SO_4)_3 + 3C_2H_4O_2 + 2K_2SO_4 + 11H_2O$$
If the rate of appearance of $$Cr_2(SO_4)_3$$ is 2.67 mol min$$^{-1}$$ at a particular time, the rate of disappearance of $$C_2H_6O$$ at the same time is _________ mol min$$^{-1}$$. (Nearest integer)

1 kg of 0.75 molal aqueous solution of sucrose can be cooled up to $$-4°$$C before freezing. The amount of ice (in g) that will be separated out is _________. (Nearest integer) [Given : $$K_f(H_2O) = 1.86$$ K kg mol$$^{-1}$$]

The number of $$f$$ electrons in the ground state electronic configuration of Np (Z = 93) is _________. (Integer answer)

The number of moles of NH$$_3$$, that must be added to 2 L of 0.80 M AgNO$$_3$$ in order to reduce the concentration of Ag$$^+$$ ions to $$5.0 \times 10^{-8}$$ M ($$K_{formation}$$ for $$[Ag(NH_3)_2]^+ = 1.0 \times 10^8$$) is _________. (Nearest integer)
[Assume no volume change on adding NH$$_3$$]

When 10 mL of an aqueous solution of KMnO$$_4$$ was titrated in acidic medium, equal volume of 0.1M of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of KMnO$$_4$$ in grams per litre is _________ $$\times 10^{-2}$$. (Nearest integer) [Atomic mass of K = 39, Mn = 55, O = 16]

The number of moles of CuO, that will be utilized in Dumas method for estimating nitrogen in a sample of 57.5 g of N, N-dimethylaminopentane is _________ $$\times 10^{-2}$$. (Nearest integer)

200 mL of 0.2 M HCl is mixed with 300 mL of 0.1 M NaOH. The molar heat of neutralization of this reaction is -57.1 kJ. The increase in temperature in °C of the system on mixing is $$x \times 10^{-2}$$. The value of x is _________. (Nearest integer)
[Given: Specific heat of water = 4.18 J g$$^{-1}$$ K$$^{-1}$$
Density of water = 1.00 g cm$$^{-3}$$]
(Assume no volume change on mixing)

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $$\frac{h^2}{x \cdot m a_0^2}$$. The value of 10x is _________. ($$a_0$$ is radius of Bohr's orbit)
(Nearest integer)
[Given: $$\pi = 3.14$$]

In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is _________. (Nearest integer)
[Atomic mass: Ag = 108, Br = 80]

1 mol of an octahedral metal complex with formula MCl$$_3$$ . 2L on reaction with excess of AgNO$$_3$$ gives 1 mol of AgCl. The denticity of Ligand L is _________. (Integer answer)