NTA JEE Main 16th March 2021 Shift 1

Complete combustion of 750 g of an organic compound provides 420 g of $$CO_2$$ and 210 g of $$H_2O$$. The percentage composition of carbon and hydrogen in organic compound is 15.3 and ________ respectively. (Round off to the Nearest Integer)

A 6.50 molal solution of KOH (aq.) has a density of 1.89 g cm$$^{-3}$$. The molarity of the solution is ________ mol dm$$^{-3}$$. (Round off to the Nearest Integer).
[Atomic masses: K: 39.0 u; O: 16.0 u; H: 1.0 u]

When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is ________ $$\mathring{A}$$ (angstrom). (Round off to the Nearest Integer).
[Use: $$\sqrt{3} = 1.73$$, $$h = 6.63 \times 10^{-34}$$ Js; $$m_e = 9.1 \times 10^{-31}$$ kg; $$c = 3.0 \times 10^{8}$$ ms$$^{-1}$$; $$1$$ eV $$= 1.6 \times 10^{-19}$$ J]

For the reaction $$A(g) \rightleftharpoons B(g)$$ at 495 K, $$\Delta_rG^\circ = -9.478$$ kJ mol$$^{-1}$$. If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B is the equilibrium mixture is ________ millimoles. (Round off to the Nearest Integer).
[$$R = 8.314$$ J mol$$^{-1}$$ K$$^{-1}$$; $$\ln 10 = 2.303$$]

Two salts $$A_2X$$ and MX have the same value of solubility product of $$4.0 \times 10^{-12}$$. The ratio of their molar solubilities i.e. $$\frac{S(A_2X)}{S(MX)}$$ = ________. (Round off to the Nearest Integer).

$$2MnO_4^- + bC_2O_4^{2-} + cH^+ \rightarrow xMn^{2+} + yCO_2 + zH_2O$$
If the above equation is balanced with integer coefficients, the value of c is ________. (Round off to the Nearest Integer).

A certain element crystallises in a bcc lattice of unit cell edge length 27 $$\mathring{A}$$. If the same element under the same conditions crystallises in the fcc lattice, the edge length of the unit cell in $$\mathring{A}$$ will be ________. (Round off to the Nearest Integer).
[Assume each lattice point has a single atom]
[Assume $$\sqrt{3} = 1.73$$, $$\sqrt{2} = 1.41$$]

$$AB_2$$ is 10% dissociated in water to $$A^{2+}$$ and $$B^-$$. The boiling point of 10.0 molal aqueous solution of $$AB_2$$ is ________ °C. (Round off to the Nearest Integer).
[Given: Molal elevation constant of water $$K_b = 0.5$$ K kg mol$$^{-1}$$, boiling point of pure water = 100°C]

The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at 300 K is $$1.0 \times 10^{-3}$$ s$$^{-1}$$ and the activation energy $$E_a = 11.488$$ kJ mol$$^{-1}$$, the rate constant at 200 K is ________ $$\times 10^{-5}$$ s$$^{-1}$$. (Round off to the Nearest Integer).
[Given $$R = 8.314$$ J mol$$^{-1}$$ K$$^{-1}$$]

The equivalents of ethylene diamine required to replace the neutral ligands from the coordination sphere of the trans-complex of $$CoCl_3 \cdot 4NH_3$$ is ________. (Round off to the Nearest Integer).