jee main chemistry important questions | Purification And Characterization Of Organic Compounds

Q 11 :

$R_{f}$ value for 2-methylpropene in a solvent system [Ethyl acetate + ether] is 0.42.

2-methylpropene is treated with dilute $H_{2} {SO}_{4}$ to give major organic product $(X)$ .

$R_{f}$ value for (X) is the same solvent system under identical condition will be: [2026]

0.42
0.82
0.62
0.12

(4)

[IMAGE 174]

As $X$ is more polar than 2-methylpropene, $X$ has stronger affinity towards the polar solvent (ethyl acetate + ether). Hence $R_{f}$ value of $X$ is lesser than that of 2-methylpropene.

Q 12 :

Given below are two statements:

Statement I: A mixture of $C_{12} H_{22} O_{11}$ (sugar) and $NaCl$ can be separated by dissolving sugar in alcohol, due to differential solubility.

Statement II: Rose essence from rose petals is separated by steam distillation due to its high volatility and insolubility in $H_{2} O$ .

In the light of the above statements, choose the correct answer from the options given below: [2026]

Both Statement I and Statement II are true
Both Statement I and Statement II are false
Statement I is true but Statement II is false
Statement I is false but Statement II is true

(1)

Statement I: A mixture of sugar and NaCl can be separated by alcohol (specifically ethanol) through a process of selective dissolution, filtration, and evaporation. Sugar is soluble in hot alcohol, while NaCl is not, allowing them to be separated based on this solubility difference.

Statement II: Rose essence (oil) is extracted by steam distillation by passing hot steam through fresh rose petals, which vaporizes the aromatic compounds. This vapor passes through a condenser, cools back into a liquid, and is separated (as the oil is water insoluble), yielding precious rose essential oil and a fragrant rose water byproduct.

Q 13 :

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 vapour 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: [2026]

Both Statement I and Statement II are true
Both Statement I and Statement II are false
Statement I is true but Statement II is false
Statement I is false but Statement II is true

(3)

The vapours rising up in the fractionating column become richer in low boiling component of the mixture.

Topic Question Set

Q 11 :

$R_{f}$ value for 2-methylpropene in a solvent system [Ethyl acetate + ether] is 0.42.

2-methylpropene is treated with dilute $H_{2} {SO}_{4}$ to give major organic product $(X)$ .

$R_{f}$ value for (X) is the same solvent system under identical condition will be: [2026]

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Topic Question Set

Q 11 : Rf value for 2-methylpropene in a solvent system [Ethyl acetate + ether] is 0.42. 2-methylpropene is treated with dilute H2SO4 to give major organic product (X). Rf value for (X) is the same solvent system under identical condition will be: [2026]

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Q 11 :

$R_{f}$ value for 2-methylpropene in a solvent system [Ethyl acetate + ether] is 0.42.

2-methylpropene is treated with dilute $H_{2} {SO}_{4}$ to give major organic product $(X)$ .

$R_{f}$ value for (X) is the same solvent system under identical condition will be: [2026]