JEE Main & Advanced Chemistry Solutions / विलयन Ideal And Non-Ideal Solution

Ideal solutions

Non-ideal solutions

Positive deviation from Raoult's law

Negative deviation from Raoult's law

1.     Obey Raoult's law at every range of concentration.

1.     Do not obey Raoult's law.

1. Do not obey Raoult's law.

2.       \[\Delta {{H}_{\text{mix}}}=0;\]neither heat is evolved nor           absorbed during dissolution. 

2.     \[\Delta {{H}_{\text{mix}}}>0.\]Endothermic dissolution; heat is absorbed. 

2. \[\Delta {{H}_{\text{mix}}}<0.\] Exothermic dissolution; heat is evolved. 

3.     \[\Delta {{V}_{\text{mix}}}=0;\]total volume of solution is equal to sum of volumes of the components.

3.     \[\Delta {{V}_{\text{mix}}}>0.\]Volume is increased after dissolution.

3.     \[\Delta {{V}_{\text{mix}}}<0.\] Volume is decreased during dissolution.

4.        \[P={{p}_{A}}+{{p}_{B}}=p_{A}^{0}{{X}_{A}}+p_{B}^{0}{{X}_{B}}\]i.e.,

        \[{{p}_{A}}=p_{A}^{0}{{X}_{A}}:{{p}_{B}}=p_{B}^{0}{{X}_{B}}\]

4.     \[{{p}_{A}}>p_{A}^{0}{{X}_{A}};\] \[{{p}_{B}}>p_{B}^{0}{{X}_{B}}\]

        \[\therefore \] \[{{p}_{A}}+{{p}_{B}}>p_{A}^{0}{{X}_{A}}+p_{B}^{0}{{X}_{B}}\]

4.     \[{{p}_{A}}<p_{A}^{0}{{X}_{A}};\]\[{{p}_{B}}<p_{B}^{0}{{X}_{B}}\]

        \[\therefore \] \[{{p}_{A}}+{{p}_{B}}<p_{A}^{0}{{X}_{A}}+p_{B}^{0}{{X}_{B}}\]

5.     \[A-A,\ A-B,\ B-B\] interactions should be same, i.e., 'A' and 'B' are identical in shape, size and character.

5.     \[A-B\] attractive force should be weaker than \[A-A\] and \[B-B\] attractive forces. 'A' and 'B' have different shape, size and character.  

5.     \[A-B\]attractive force should be greater than \[A-A\] and \[B-B\] attractive forces. 'A' and 'B' have different shape, size and character.

6.     Escaping tendency of 'A' and 'B' should be same in pure liquids and in the solution.

6.     'A' and 'B' escape easily showing higher vapour pressure than the expected value.

6.     Escaping tendency of both components 'A' and 'B' is lowered showing lower vapour pressure than expected ideally.

Examples:

Dilute solutions;

benzene + toluene:

n-hexane + n-heptane;

chlorobenzene + bromobenzene;

ethyl bromide + ethyl iodide;

n-butyl chloride + n-butyl bromide

Examples:

Acetone +ethanol

acetone +\[C{{S}_{2}}\]:

water + methanol;

water + ethanol;

\[CC{{l}_{4}}+\]toluene;

\[CC{{l}_{4}}+CHC{{l}_{3}}\];

acetone + benzene;

\[CC{{l}_{4}}+C{{H}_{3}}OH\];

cyclohexane + ethanol

Examples:

Acetone + aniline;

acetone + chloroform;

\[C{{H}_{3}}OH\ +\ C{{H}_{3}}COOH\];

\[{{H}_{2}}O\ +\ HN{{O}_{3}}\]

chloroform + diethyl ether;

water + HCl;

acetic acid + pyridine;

chloroform + benzene