NON-IDEAL system-azeotropes-hcl-h20 and ethanol -water system

NON-IDEAL system-azeotropes -hcl-h20 and ethanol -water system

1. CHEMISTRY
SEMINAR Presented by ALINTA MARIA Non ideal system - azeotropes - Hcl-H2O
and ethanol -water system Submitted to,
Mr.S Detchanamurthy
faculty of chemistry
dept. Of education
NITPY Karaikal

2. NON-IDEAL SYSTEM
What is a non-ideal system?
When a solution does not obey Raoult's law for all the
concentration and temperature ranges, it is known as a
non-ideal solution.
A non-ideal solution may show positive or negative
deviation from Raoult's law. ΔHmix and ΔVmix for non-
ideal solutions are not equal to zero.

3. NON IDEAL SYSTEM WITH POSITIVE DEVIATION
Positive deviation from Raoult's law when intermolecular
forces between different molecules (A-B) are weaker than
those between similar molecules (A-A, B-B),
A-B
A-A
B-B>

4. NON IDEAL SYSTEM WITH NEGATIVE DEVIATION
they show negative deviation when A-B forces are stronger
than A-A and B-B forces, resulting in a lower vapor pressure.
A-B
A-A
B-B<

5. AZEOTROPES A mixture that boils at a constant temperature with no change in composition
between the liquid and vapor phases. This occurs because the interactions between
the mixture's molecules are different from the interactions in the pure components.
Non-ideal solutions with a positive deviation from Raoult's Law form minimum-
boiling azeotropes, while those with a negative deviation form maximum-boiling
azeotropes.

Characteristics of azeotropes in non-ideal systems
Constant boiling point:
Constant composition:
No separation by fractional distillation:

6. Minimum-boiling azeotrope: Formed by solutions with a positive deviation from
Raoult's Law.
The interactions between the different molecules are weaker than the interactions in
the pure components. This results in a higher vapor pressure than predicted by
Raoult's Law. The azeotrope boils at a temperature lower than either of the pure
components. An example is the ethanol-water mixture.
Maximum-boiling azeotrope: Formed by solutions with a negative deviation from
Raoult's Law.
The interactions between the different molecules are stronger than the interactions
in the pure components. This results in a lower vapor pressure than predicted by
Raoult's Law. The azeotrope boils at a temperature higher than either of the pure
components. An example is the nitric acid-water mixtureTYPES OF NON-IDEAL AZEOTROPES

7. ETHANOL - WATER SYSTEM The ethanol-water system forms a minimum boiling azeotrope with a boiling
point lower than either component, at approximately 95.6% ethanol and 78.2°C.Type: Minimum boiling azeotrope.
Composition: Approximately 95.6% ethanol and 4.4% water by mass.
Boiling point: ~78.2°C, which is lower than the boiling point of pure ethanol
(78.5°C) and pure water (100°C).
Deviation from Raoult's Law: Positive deviation.
Separation limitation: Simple distillation cannot separate the components
beyond this azeotropic composition because the vapor has the same
composition as the liquid.

8. HCL - WATER SYSTEM The HCl-water system forms a maximum boiling azeotrope at about 20.2% HCl,
which boils at a higher temperature (108.6°C) than pure water or pure HCl. Type: Maximum boiling azeotrope.
Composition: Approximately 20.2% HCl and 79.8% water by mass.
Boiling point: 108.6°C, which is higher than the boiling point of pure water
(100°C) and pure HCl (~$85.1$°C).
Deviation from Raoult's Law: Negative deviation.
Separation limitation: Simple distillation cannot separate the components
beyond this azeotropic compositio

9. QUESTIONS Qn.1(JAM.2017)
which of the following mixtures forms a minimun boiling azeotropes?
A) water & acetic acid
b) water & hydrochloric acid
c) ethanol & acetone.
d)chloroform & acetone
Ans: C)ethanol & acetone.
Pure ethanol molecules are held together by strong hydrogen bonds . When acetone is
added, the non-polar part of acetone disrupts the hydrogen bonding network of
ethanol. This makes the A-B interactions weaker than the A-A interactions, leading to a
positive deviation.

10. QUESTIONS Qn.1(JAM.2017)
which of the following mixtures forms a minimun boiling azeotropes?
A) water & acetic acid
b) water & hydrochloric acid
c) ethanol & acetone.
d)chloroform & acetone
Ans: C)ethanol & acetone.
Pure ethanol molecules are held together by strong hydrogen bonds . When acetone is
added, the non-polar part of acetone disrupts the hydrogen bonding network of
ethanol. This makes the A-B interactions weaker than the A-A interactions, leading to a
positive deviation.

11. QUESTIONS Qsn.2(JAM.2017)
The azeotropic mixtures of water (B-P-100°C) and Hcl (B.P=85°c) boils at 108.5°c.
when this mixture is allowed to distilled, What can be obtained?
A) pure Hcl
B)Pure H20
C) pure h20 and pure Hcl
D)Neither pure Hcl ,nor pure h20
Ans : D) Neither Pure Hcl nor pure H20
Since the vapour & liquid composition are at the same at this point, the mixture
distills over a whole without a change in composition, and no pure component is
obtained.

12. QUESTIONS Qsn 3 (JAM 2022-style)
Which of the following pairs of liquids is expected to show the strongest intermolecular
forces of attraction upon mixing, resulting in a negative deviation from Raoult's law?
A. \(CH_{3}COCH_{3}\) and \(CS_{2}\)
B. \(CHCl_{3}\) and \(CH_{3}COCH_{3}\)
C. \(C_{2}H_{5}OH\) and \(H_{2}O\)
D. \(C_{6}H_{6}\) and \(C_{6}H_{5}CH_{3}\)
B. \(CHCl_{3}\) and \(CH_{3}COCH_{3}\
The hydrogen atom of chloroform is slightly acidic and can form a hydrogen bond with
the lone pair on the oxygen atom of acetone. This creates a new, stronger interaction in
the solution compared to the forces in the pure components, causing a negative
deviation.

13. QUESTIONS Qsn .4
For a non-ideal solution with a positive deviation from Raoult's law, what is the sign of
the enthalpy of mixing (\(\Delta H_{mix}\))?
A. \(\Delta H_{mix}>0\)
B. \(\Delta H_{mix}<0\)
C. \(\Delta H_{mix}=0\)
D. It depends on the concentration.
ans:option(a)
In a solution with a positive deviation, the intermolecular forces become weaker upon
mixing, so energy must be supplied to break the stronger bonds in the pure
components. This makes the mixing process endothermic, and the enthalpy of mixing
is positive (\(\Delta H_{mix}>0\)).

14. QUESTIONS Qsn.5
What is the defining characteristic of an azeotropic mixture?
A. It boils at a constant temperature
B. It can be separated by simple distillation
C. It always has a boiling point lower than its components
D. It always shows a negative deviation from Raoult's law
Ans:option(a)
An azeotrope is also known as a "constant boiling mixture" because its
composition in the vapor phase is the same as in the liquid phase at its boiling
point. This means it boils at a constant temperature, and simple distillation
cannot separate the components further.

15. REFERENCE Principles of physical chemistry. [163-166]
Madan S pathania B-R-Puri L.R.sharma.
Vishal publishing Co.
Chemistry part-1 textbook for class XII. [13-14)
Principles of physical chemistry. [284-285)
Samual H. Maron Carl F.Poutton.
CBs publishers & distri Butoxs.
https: // share.google/b2ZJLln3B4+B604LE.
https:/youtu.be/k189x4AxwMye ? si = maRL3j6-g Bladk97

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