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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The H-O-H bond angle in water molecule is 104.5°.
Reason R: The lone pair - lone pair repulsion of electrons is higher than the bond pair - bond pair repulsion.
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Given below are two statements:
Statement I: $$H_2O_2$$ can act as both oxidising and reducing agent in basic medium.
Statement II: In the hydrogen economy, the energy is transmitted in the form of dihydrogen. In the light of the above statements, choose the correct answer from the options given below:
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A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The element is:
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Given below are two statements:
Statement I: Both $$CaCl_2 \cdot 6H_2O$$ and $$MgCl_2 \cdot 8H_2O$$ undergo dehydration on heating.
Statement II: BeO is amphoteric, whereas the oxides of other elements in the same group are acidic.
In the light of the above statements, choose the correct answer from the options given below:
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Among the following, the aromatic compounds are:
Choose the correct answer from the following options:
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Assertion A: Enol form of acetone [$$CH_3COCH_3$$] exists in < 0.1% quantity. However, the enol form of acetyl acetone [$$CH_3COCH_2OCCH_3$$] exists in approximately 15% quantity.
Reason R: enol form of acetyl acetone is stabilized by intramolecular hydrogen bonding, which is not possible in enol form of acetone.
Choose the correct statement:
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In chromatography technique, the purification of a compound is independent of:
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The product "A" and "B" formed in below reactions are:
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The type of pollution that gets increased during the daytime and in the presence of $$O_3$$ is:
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Given below are two statements:
Statement I: The E° value of $$Ce^{4+}/Ce^{3+}$$ is +1.74 V.
Statement II: Ce is more stable in $$Ce^{4+}$$ state than $$Ce^{3+}$$ state.
In the light of the above statements, choose the most appropriate answer from the options given below:
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The process that involves the removal of sulphur from the ores is:
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Match List-I with List-II:
Choose the correct answer from the options given below:
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Match List-I with List-II:
Choose the correct answer from the options given below:
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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: Size of $$Bk^{3+}$$ ion is less than $$Np^{3+}$$ ion.
Reason R: The above is a consequence of the lanthanide contraction.
In the light of the above statements, choose the correct answer from the options given below:
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Which of the following is Lindlar catalyst?
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The product "P" in the above reaction is:
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In the above chemical reaction, intermediate "X" and reagent/condition "A" are:
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Which of the following reaction DOES NOT involve Hoffmann Bromamide degradation?
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The functions of antihistamine are:
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Which among the following pairs of Vitamins is stored in our body relatively for longer duration?
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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)
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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]
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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]
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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$$^{-1}$$; $$\ln 10 = 2.303$$]
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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).
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$$2MnO_4^- + bC_2O_4^{2-} + cH^+ \rightarrow xMn^{2+} + yCO_2 + zH_2O$$
If the above equation is balanced with integer coefficients, the value of c is ________. (Round off to the Nearest Integer).
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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 $$\sqrt{3} = 1.73$$, $$\sqrt{2} = 1.41$$]
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$$AB_2$$ 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]
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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$$^{-1}$$]
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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).
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