The Question is from neet-chemistry basic-chemistry-concepts , and it was created by the author THIRUPATHI REDDY

Question

A binary liquid mixture of components A and B exhibits an azeotrope at a specific composition. Which of the following statements is ALWAYS true about this azeotropic mixture?

THIRUPATHI REDDY · Accepted Answer

## CORE INFORMATION
✓ **Answer**: A
## CONCEPT FRAMEWORK
 **Primary Concept**: Azeotropes and Raoult's Law
 **Related Topics**: Vapor-liquid equilibrium, distillation
 **Prerequisites**: Understanding of vapor pressure, mole fractions, and Raoult's Law.
## SOLUTION PATHWAY
**Given Information**:
A binary liquid mixture of A and B forms an azeotrope.
**Method & Steps**:
1. Understanding Azeotropes: An azeotrope is a mixture of two or more liquids whose proportions cannot be altered by simple distillation. This is because the vapor phase has the same composition as the liquid phase at the boiling point.
  Reasoning: The defining characteristic of an azeotrope is that the liquid and vapor compositions are identical at its boiling point.
  Formula/Rule:  At the azeotropic point, $x_A = y_A$ and $x_B = y_B$, where $x_i$ is the mole fraction of component $i$ in the liquid phase and $y_i$ is the mole fraction in the vapor phase.
2. Analyzing the options:
  Working: Let's examine each option:
  A. This statement is the definition of an azeotrope. It's always true.
  B. The boiling point of an azeotrope is not necessarily the average of the boiling points of pure A and B. It can be higher or lower.
  C. Azeotropes cannot be separated by simple fractional distillation because the vapor and liquid compositions are identical.  Special techniques are required.
  D. Azeotropes can exhibit either positive or negative deviations from Raoult's Law.  It's not always a positive deviation.
 3. Conclusion:
  Result: Option A is always true for an azeotropic mixture.
  Verification: The definition of an azeotrope confirms this.
 ## OPTION ANALYSIS
A ✓: The composition of the vapor phase is identical to the composition of the liquid phase. This is the defining characteristic of an azeotrope.
B :x: The boiling point of an azeotrope can be higher or lower than the average of the boiling points of the pure components.
C :x: Azeotropes cannot be separated by simple fractional distillation because the vapor and liquid compositions are the same.
D :x: Azeotropes can show either positive or negative deviations from Raoult's Law, depending on the intermolecular interactions between the components.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing azeotropes with ideal solutions: Azeotropes are non-ideal solutions.
  How to avoid: Remember that Raoult's Law only applies to ideal solutions. Azeotropes deviate from Raoult's Law.
  2.Assuming the boiling point of an azeotrope is always an average: The boiling point can be higher or lower.
  How to avoid: Understand that intermolecular forces play a significant role in determining the boiling point of an azeotrope.
 **Quick Tips**:
  1.Remember the key characteristic of an azeotrope:  $x_A = y_A$ and $x_B = y_B$
  2.Azeotropes require special separation techniques (e.g., pressure-swing distillation) beyond simple fractional distillation.

THIRUPATHI REDDY · Answer

The correct Option is "The composition of the vapor phase is identical to the composition of the liquid phase."

THIRUPATHI REDDY · Answer

The boiling point of the azeotrope is the average of the boiling points of pure A and B.

THIRUPATHI REDDY · Answer

The azeotrope can be separated into pure A and B by fractional distillation.

THIRUPATHI REDDY · Answer

The azeotrope always shows a positive deviation from Raoult's Law.

NEET Chemistry Some Basic Concepts in Chemistry MCQs

Select Topic

Question Tags

NEET Subjects

Our Bots

Company