Given below are two statements :
Statement I: A mixture of chloroform and aniline can be separated b

Q: Why can't we use fractional distillation for chloroform and aniline?

Fractional distillation is used when the boiling point difference is small (less than $25 \text{ K}$). Since the difference here is $123 \text{ K}$, simple distillation is perfectly adequate, much faster, and requires less complex apparatus.

Q: Does aniline dissolve in water during steam distillation?

No, aniline is immiscible with water. This is a crucial requirement for steam distillation, allowing their vapor pressures to act independently and add up to reach atmospheric pressure faster.

Q: Why does the mixture boil at a lower temperature in steam distillation?

Because both water and the organic liquid contribute to the total vapor pressure ($P_{\text{total}} = P_{\text{water}} + P_{\text{organic}}$). The total pressure reaches $1 \text{ atm}$ at a lower temperature than either pure liquid would on its own.

Q: What happens to the aniline after steam distillation?

The distillate collected contains both water and aniline. Since they are immiscible, they form two separate layers in the receiver flask, which can be easily separated using a separating funnel.

Q: Is steam distillation only used for aniline?

Not at all! It is used for many organic compounds that are steam volatile, immiscible with water, and might decompose at their normal, high boiling points (e.g., extracting essential oils from plants).

Question

Given below are two statements :
Statement I A mixture of chloroform and aniline can be separated by simple distillation.
Statement II When separating aniline from a mixture of aniline and water by steam distillation aniline boils below its boiling point.
In the light of the above statements, choose the most appropriate answer from the options given below.

Options:

(A) Statement I is false but statement II is true

(B) Both statement I and statement II are false

(C) Statement I is true but statement II is false

(D) Both statement I and statement II are true

Sigma Percentile · Accepted Answer

The purification of organic compounds is a fascinating blend of physical chemistry and practical laboratory techniques. In this problem, we are tasked with evaluating two distinct separation methods: simple distillation and steam distillation. Let's break down the science behind each statement to uncover the truth.

### Analyzing Statement I: Simple Distillation

Statement I claims that a mixture of chloroform and aniline can be separated by simple distillation. To verify this, we must look at the fundamental requirement for simple distillation: a significant difference in boiling points between the components, typically greater than $25 	ext{ K}$.

Let's check the data:
- The boiling point of chloroform ($	ext{CHCl}_3$) is $334 	ext{ K}$.
- The boiling point of aniline ($	ext{C}_6	ext{H}_5	ext{NH}_2$) is $457 	ext{ K}$.

The difference in their boiling points is:

$$\Delta T_b = 457 	ext{ K} - 334 	ext{ K} = 123 	ext{ K}$$

This difference of $123 	ext{ K}$ is massive! Because the gap is so large, simple distillation will work flawlessly. When the mixture is heated, the highly volatile chloroform will vaporize first, travel through the condenser, and be collected as a pure liquid, leaving the high-boiling aniline behind in the distillation flask. Therefore, **Statement I is absolutely true**.

### Analyzing Statement II: The Magic of Steam Distillation

Statement II introduces steam distillation for separating aniline from water. Aniline is a high-boiling liquid ($457 	ext{ K}$) that is immiscible with water. If we tried to boil aniline normally, it might decompose at such high temperatures. This is where steam distillation comes to the rescue.

Because aniline and water are immiscible, they do not interact to lower each other's vapor pressure like miscible liquids do (Raoult's Law does not apply here). Instead, they act independently. According to Dalton's Law of Partial Pressures, the total vapor pressure above the mixture is simply the sum of their individual vapor pressures:

$$P_{	ext{total}} = P_{	ext{water}} + P_{	ext{aniline}}$$

### The Vapor Pressure Graph

A liquid boils when its total vapor pressure equals the atmospheric pressure ($P_{	ext{atm}}$). In our mixture, both water and aniline are contributing to the total pressure.

Because $P_{	ext{total}}$ is the sum of two positive values, it will reach $1 	ext{ atm}$ at a temperature *lower* than the boiling point of pure water ($373 	ext{ K}$) and significantly lower than the boiling point of pure aniline ($457 	ext{ K}$).

This means the mixture will boil at a temperature $T_{	ext{mix}} < 373 	ext{ K}$. Consequently, aniline is forced to vaporize and distill over at a temperature far below its normal boiling point, protecting it from thermal decomposition. Thus, **Statement II is also perfectly true**.

### Conclusion

Since both statements are conceptually and factually correct, the most appropriate answer is that both Statement I and Statement II are true.

Select Answer:

Visualized Solution

$S t a t e m e n t I : S im pl eD i s t i l l a t i o n$

$B o i l in g P o in t D i f f er e n ce$

$S t a t e m e n t I I : S t e am D i s t i l l a t i o n$

$B o i l in g P o in t o f I mmi sc ib l e M i x t u r e$

$C o n c l u s i o n$

$F ina l A n s w er$

$T h e W a y F or w a r d$

The Sigma Insight: Nomenclature and Characterisation

Analyzing Statement I

Analyzing Statement II

The Vapor Pressure Graph

Conclusion

Similar Questions

The correct match between items I and II is $Item I (Mixture) A. H_{2} O : Sugar B. H_{2} O : Aniline C. H_{2} O : Toluene Item II (Separation method) P. Sublimation Q. Recrystallisation R. Steam distillation S. Differential extraction$

Which purification technique is used for high boiling organic liquid compound (decomposes near its boiling point)?

A flask contains a mixture of isohexane and 3-methylpentane. One of the liquids boils at $6 3^{\circ} C$ while the other boils at $6 0^{\circ} C$ . What is the best way to separate the two liquids and which one will be distilled out first?

If dichloromethane (DCM) and water ( $H_{2} O$ ) are used for differential extraction, which one of the following statements is correct?

Given below are two statements. Statement I Retardation factor ( $R_{f}$ ) can be measured in metre/centimetre. Statement II $R_{f}$ value of a compound remains constant in all solvents. Choose the most appropriate answer from the options given below

The organic compound that gives following qualitative analysis is $Test (i) Dil. HCl (ii) NaOH solution (iii) Br_{2} /water Inference Insoluble Soluble Decolourisation$

Glycerol is separated in soap industries by

Select Answer:

Visualized Solution

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } StatementI:SimpleDistillation

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } BoilingPointDifference

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } StatementII:SteamDistillation

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } BoilingPointofImmiscibleMixture

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } Conclusion

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } FinalAnswer

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } TheWayForward