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At 300 K and 1 atm, 15 mL of a gaseous hydrocarbon requires 375 mL air containing 20% $$O_2$$ by volume, for complete combustion. After combustion, the gases occupy 345 mL. Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is: (Assume complete combustion of reactant)
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A stream of electrons from a heat filament was passed between two charge plates kept at a potential difference V esu. If e and m are charge and mass of an electron, respectively, then the value of $$\frac{h}{\lambda}$$ (where $$\lambda$$ is wavelength associated with the electron wave) is given by:
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Which of the following atoms has the highest first ionization energy?
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The species in which the N atom is in a state of sp hybridization is:
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Two closed bulbs of equal volume (V) containing an ideal gas initially at pressure $$p_i$$ and temperature $$T_1$$ are connected through a narrow tube of negligible volume, as shown in the figure below. The temperature of one of the bulbs is then raised to $$T_2$$. The final pressure $$P_f$$ is:
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The heats of combustion of carbon and carbon monoxide are $$-393.5$$ and $$-283.5$$ kJ mol$$^{-1}$$, respectively. The heat of formation (in kJ) of carbon monoxide per mole is:
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The equilibrium constant at 298 K for a reaction $$A + B \rightleftharpoons C + D$$ is 100. If the initial concentration of all the four species were 1 M each, then the equilibrium concentration of D (in mol $$L^{-1}$$) will be:
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Which of the following statements about water is FALSE?
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The main oxides formed on combustion of Li, Na and K in excess of air are respectively:
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The absolute configuration of
is:
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The distillation technique most suited for separating glycerol from spent - lye in the soap industry is:
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The reaction of propene with HOCl ($$Cl_2 + H_2O$$) proceeds through the intermediate:
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The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to high concentration of:
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18 g glucose ($$C_6H_{12}O_6$$) is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is:
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Galvanization is applying a coating of:
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Decomposition of $$H_2O_2$$ follows a first order reaction. In fifty minutes the concentration of $$H_2O_2$$ decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of $$H_2O_2$$ reaches 0.05 M, the rate of formation of $$O_2$$ will be:
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For a linear plot of log $$\left(\frac{x}{m}\right)$$ versus log p in a Freundlich adsorption isotherm, which of the following statements is correct? (k and n are constants)
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The hottest region of Bunsen flame shown in the figure below is:
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Which one of the following ores is best concentrated by froth flotation method?
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The pair in which phosphorous atoms have a formal oxidation state of +3 is:
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The reaction of zinc with dilute and concentrated nitric acid, respectively, produces:
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Find the metallic and ferromagnetic substance.
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Which one of the following complexes shows optical isomerism? (en=ethylenediamine)
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The pair having the same magnetic moment is: [At. No.: Cr = 24, Mn = 25, Fe = 26, Co = 27]
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The product of the reaction given below is:
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2-chloro-2-methylpentane on reaction with sodium methoxide in methanol yields:
(i)
(ii)
(iii)
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In the Hoffmann bromamide degradation reaction, the number of moles of NaOH and $$Br_2$$ used per mole of amine produced are:
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Which of the following statements about low density polythene is FALSE?
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Which of the following is an anionic detergent?
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Thiol group is present in:
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