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$$120$$ g of an organic compound which contains only carbon and hydrogen on complete combustion gives $$330$$ g of $$CO_2$$ and $$270$$ g of water. The percentage of carbon and hydrogen in the organic compound are respectively
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The energy of one mole of photons of radiation of wavelength $$300$$ nm is (Given :
$$h = 6.63 \times 10^{-34}$$ J s, $$N_A = 6.02 \times 10^{23}$$ mol$$^{-1}$$, $$c = 3 \times 10^{8}$$ m s$$^{-1}$$)
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Metals generally melt at very high temperatures, Among the following which one has the highest melting point?
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The correct order of bond orders of $$C_2^{2-}$$, $$N_2^{2-}$$ and $$O_2^{2-}$$ is
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At $$25°$$C and 1 atm pressure, the enthalpies of combustion are as given below:
| Substance | $$H_2$$ | C (graphite) | $$C_2H_6(g)$$ |
|---|---|---|---|
| $$\frac{\Delta_c H^\ominus}{kJ mol^{-1}}$$ | $$-286.0$$ | $$-394.0$$ | $$-1560.0$$ |
The enthalpy of formation of ethane is
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Which one of the following compounds is used as a chemical in certain type of fire extinguishers
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Arrange the following carbocations in decreasing order of stability.
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Given below are two statements.
Statement I: The presence of weaker $$\pi$$-bonds make alkenes less stable than alkanes
Statement II: The strength of the double bond is greater than that of carbon-carbon single bond.
In the light of the above statements, choose the correct answer from the options given below.
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Which of the following reagents / reactions will convert 'A' to 'B'?
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Some gases are responsible for heating of atmosphere (green house effect). Identify from the following the gaseous species which does not cause it.
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In the industrial production of which of the following, molecular hydrogen is obtained as a bye product.
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For a first order reaction, the time required for completion of $$90\%$$ reaction is '$$x$$' times the half life of the reaction. The value of '$$x$$' is
(Given: $$\ln 10 = 2.303$$ and $$\log 2 = 0.3010$$)
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Which of the following chemical reactions represents Hall-Heroult Process?
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$$PCl_5$$ is well known but $$NCl_5$$ is not. Because,
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Transition metal complex with highest value of crystal field splitting $$(\Delta_0)$$ will be
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Hex-4-ene-2-ol on treatment with PCC gives 'A'. 'A' on reaction with sodium hypoiodite gives 'B', which on further heating with soda lime gives 'C'. The compound 'C' is
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The conversion of propan-1-ol to n-butylamine involves the sequential addition of reagents. The correct sequential order of reagents is
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Which of the following is not a condensation polymer?
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The structure shown below is of which well-known drug molecule?
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In the flame test of a mixture of salts, a green flame with blue centre was observed. Which one of the following cations may be present?
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At $$300$$ K, a sample of $$3.0$$ g of gas A occupies the same volume as $$0.2$$ g of hydrogen at $$200$$ K at the same pressure. The molar mass of gas A is ______ g mol$$^{-1}$$. (nearest integer) Assume that the behaviour of gases as ideal.
(Given: The molar mass of hydrogen ($$H_2$$) gas is $$2.0$$ g mol$$^{-1}$$.)
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$$PCl_5$$ dissociates as $$PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$$. $$5$$ moles of $$PCl_5$$ are placed in a $$200$$ litre vessel which contains $$2$$ moles of $$N_2$$ and is maintained at $$600$$ K. The equilibrium pressure is $$2.46$$ atm. The equilibrium constant $$K_p$$ for the dissociation of $$PCl_5$$ is ______ $$\times 10^{-3}$$. (nearest integer) (Given: $$R = 0.082$$ L atm K$$^{-1}$$ mol$$^{-1}$$; Assume ideal gas behaviour)
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Manganese (VI) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is ______
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$$0.2$$ g of an organic compound was subjected to estimation of nitrogen by Dumas method in which volume of $$N_2$$ evolved (at STP) was found to be $$22.400$$ mL. The percentage of nitrogen in the compound is ______ [nearest integer] (Given: Molar mass of $$N_2$$ is $$28$$ g mol$$^{-1}$$, Molar volume of $$N_2$$ at STP: $$22.4$$ L)
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A company dissolves '$$x$$' amount of $$CO_2$$ at $$298$$ K in $$1$$ litre of water to prepare soda water. $$X = $$ ______ $$\times 10^{-3}$$ g. (nearest integer)
(Given: partial pressure of $$CO_2$$ at $$298$$ K $$= 0.835$$ bar. Henry's law constant for $$CO_2$$ at $$298$$ K $$= 1.67$$ kbar. Atomic mass of H, C and O is $$1, 12,$$ and $$6$$ g mol$$^{-1}$$, respectively)
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The resistance of a conductivity cell containing $$0.01$$ MKCl solution at $$298$$ K is $$1750$$ $$\Omega$$. If the conductivity of $$0.01$$ MKCl solution at $$298$$ K is $$0.152 \times 10^{-3}$$ S cm$$^{-1}$$, then the cell constant of the conductivity cell is ______ $$\times 10^{-3}$$ cm$$^{-1}$$
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When $$200$$ mL of $$0.2$$ M acetic acid is shaken with $$0.6$$ g of wood charcoal, the final concentration of acetic acid after adsorption is $$0.1$$ M. The mass of acetic acid adsorbed per gram of carbon is ______ g.
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(a) Baryte, (b) Galena, (c) Zinc blende and (d) Copper pyrites. How many of these minerals are sulphide based? ______
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Consider the above reaction. The number of $$\pi$$ electrons present in the product 'P' is ______
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In alanylglycylleucylalanylvaline the number of peptide linkages is: ______
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