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\( 0.25 \, \text{g} \) of an organic compound “A” containing carbon, hydrogen and oxygen was analyzed using the combustion method. There was an increase in mass of \( \mathrm{CaCl_2} \) tube and potash tube at the end of the experiment. The amount was found to be \( 0.15 \, \text{g} \) and \( 0.1837 \, \text{g} \), respectively. The percentage of oxygen in compound A is ______ \( \% \). (Nearest integer)
(Given: molar mass in \( \text{g mol}^{-1} \) H : \( 1 \), C : \( 12 \), O : \( 16 \))

Arrange the following alkenes in decreasing order of stability.

Choose the correct answer from the options given below:

Match List - I with List - II.

List – I Pair of Compounds	List – II Type of isomers
A. 2-Methylpropene and but-1-ene	I. Stereoisomers
B. Cis-but-2-ene and trans-but-2-ene	II. Position isomers
C. 2-Butanol and diethyl ether	III. Chain isomers
D. But-1-ene and but-2-ene	IV. Functional group isomers

Choose the correct answer from the options given below:

\( 2.0 \, \text{g} \) of a bromo hydrocarbon \( (X) \) was subjected to Carius analysis, gave \( 3.36 \, \text{g} \) of \( \text{AgBr} \). The percentage of carbon in the compound \( (X) \) is \( 26.7\% \). Total number of carbon atoms in the empirical formula for compound \( (X) \) is ________. (Given molar mass in \( \text{g mol}^{-1} \) \( \text{H}: 1, \text{C}: 12, \text{Br}: 80, \text{Ag}: 108 \))

Find out the statements which are not true.
(A) Resonating structures with more number of covalent bonds and lesser charge separation are more stable.
(B) In electromeric effect, an unsaturated system shows +E effect with nucleophile and -E effect with electrophile.
(C) Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.
(D) The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.
(E) Stability of carbanion increases with the increase in s – character of the carbon carrying the negative charge.
Choose the correct answer from the options given below:

From the following, the least stable structure is:

In an estimation of sulphur by Carius method \( 0.2 \, \text{g} \) of the substance gave \( 0.6 \, \text{g} \) of \( \mathrm{BaSO_4} \). The percentage of sulphur in the substance is ______ \( \% \).
(Given molar mass in \( \text{g mol}^{-1} \) \( \mathrm{S} : 32 \), \( \mathrm{BaSO_4} : 231 \) )

Given below are two statements:
Statement-I: Sublimation is used for the separation and purification of compounds with low melting point.
Statement-II: The boiling point of a liquid increases as the external pressure is reduced.
In the light of the above statements, choose the correct answer from the options given below:

In Carius method \( 0.2425 \, \text{g} \) of an organic compound gave \( 0.5253 \, \text{g} \) silver chloride. The percentage of chlorine in the organic compound is :

10.

The IUPAC name of the following compound is:

11.

Identify correct statements from the following:
A. Propanal and propanone are functional isomers.
B. Ethoxyethane and methoxypropane are metamers.
C. But-\( 2 \)-ene shows optical isomerism.
D. But-\( 1 \)-ene and but-\( 2 \)-ene are functional isomers.
E. Pentane and \( 2 \), \( 2 \)-dimethyl propane are chain isomers.
Choose the correct answer from the options given below:

12.

Given below are two statements:
Statement I: \( (\text{CH}_3)_3 \overset{\oplus}{\text{C}}\) is more stable than \( \overset{\oplus}{\text{C}}H_3 \) as nine hyperconjugation interactions are possible in \( (\text{CH}_3)_3 \overset{\oplus}{\text{C}}\).
Statement II: \( \overset{\oplus}{\text{C}}H_3 \) is less stable than \( (\text{CH}_3)_3 \overset{\oplus}{\text{C}} \) as only three hyperconjugation interactions are possible in \( \overset{\oplus}{\text{C}}H_3\).
In the light of the above statements, choose the correct answer from the options given below:

13.

In Dumas method for estimation of nitrogen, \( 0.50 \, \text{g} \) of an organic compound gave \( 70 \, \text{mL} \) of nitrogen collected at \( 300 \, \text{K} \) and \( 715 \, \text{mm} \) pressure. The percentage of nitrogen in the organic compound is ______ \( \% \). (Aqueous tension at \( 300 \, \text{K} \) is \( 15 \, \text{mm} \).)

14.

Sodium fusion extract of an organic compound \( (\mathrm{Y}) \) with \( \mathrm{CHCl_{3}} \) and chlorine water gives violet color to the \( \mathrm{CHCl_{3}} \) layer. \( 0.15 \,\mathrm{g} \) of \( (\mathrm{Y}) \) gave \( 0.12 \,\mathrm{g} \) of the silver halide precipitate in Carius method. Percentage of halogen in the compound \( (\mathrm{Y}) \) is __________. (Nearest integer)
(Given: molar mass \( \mathrm{g\,mol^{-1}} \) \( \mathrm{C} : 12 \), \( \mathrm{H} : 1 \), \( \mathrm{Cl} : 35.5 \), \( \mathrm{Br} : 80 \), \( \mathrm{I} : 127 \) )

15.

In IUPAC nomenclature, the correct of decreasing priority of functional group is:

16.

Given below are two statements:
Statement-I: Vapours of the liquid with higher boiling point condense before vapours of the liquid with lower boiling points in fractional distillation.
Statement-II: The vapours rising up in the fractionating column become richer in high boiling component of the mixture.
In the light of the above statements, choose the correct answer from the options given below:

17.

Given below are two statements:
Statement I: \( 2,6 \)-diethylcyclohexanone and \( 6 \)-methyl-\( 2 \)-n-propylcyclohexanone are metamers
Statement II: \( 2,2,6,6 \)-tetramethylcyclohexanone exhibits keto-enol tautomerism.
In the light of the above statements, choose the correct answer from the options given below:

18.

Arrange the following carbanions in the decreasing order of stability.

Choose the correct answer from the options given below:

19.

In Carius method, \( 0.75 \, \mathrm{g} \) of an organic compound gave \( 1.2 \, \mathrm{g} \) of barium sulphate, find percentage of sulphur (molar mass \( 32 \, \mathrm{g\,mol^{-1}} \)). Molar mass of barium sulphate is \( 233 \, \mathrm{g\,mol^{-1}} \).

20.

Given below are two statements:
Statement I: On the basis of inductive effect, the order of stability of alkyl carbanions is \( \mathrm{CH_3^-} > \mathrm{CH_3{-}CH_2^-} > (\mathrm{CH_3})_2\mathrm{CH^-} > (\mathrm{CH_3})_3\mathrm{C^-} \).
Statement II: Allyl and benzyl carbanions are more stabilised by inductive effect and not by resonance effect.
In the light of the above statements, choose the correct answer from the options given below

21.

The total number of aromatic compounds/species from the following is:

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