IDEAL SOLUTION: An ideal solution may be defined as the solution which obeys Raoult’s law over the entire range of concentration and temperature and during the formation of which no change in enthalpy and no change in volume takes place. The conditions for an ideal solution are:
1. ΔVmixing = 0
2. ΔHmixing = 0
3. A—A interaction = A—B interaction = B—B interaction.
NON-IDEAL SOLUTION: A solution which does not obey raoult's law is called non ideal solution.
1. ΔVmixing ≠ 0
2. ΔHmixing ≠ 0
3. A—A interaction ≠ A—B interaction ≠ B—B interaction.
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Ideal Solution
| Non-Ideal Solutions
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Solutions which obey Raoult’s law over the entire range of concentrations are called ideal solution.
| Solutions which do not obey Raoult’s law over the entire range of concentration
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The graph for the ideal solution can be shown as: | The graph for the non - ideal solution can be shown as: |
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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. 2.?Hmix = 0; neither is evolved nor absorbed during dissolution. 3.?Vmix = 0; total volume of solution is equal to sum of volumes of the components. 4.P = pA + pB = pA0XA + pB0XB i.e., pA = 5.A—A, A—B, B—B interactions should be same, i.e., ‘A’ and ‘B’ are identical in shape, size and character. 6. Escaping tendency of ‘A’ and ‘B’ should be same in pure liquids and in the solution. Examples: dilute solutions; benzene + toluence: n-hexane + n-heptane; chlorobenzene + bromobenzene; n-butyl chloride + n-butyl bromide. | 1.Do not obey Raoult’s law. 2.?Hmix>0. Endothermic dissolution; heat is absorbed. 3.?Vmix > 0. Volume is increased after dissolution.
4.pA > pA0XA; pB > pB0XB 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. 6. ‘A’ and B’ escape easily showing higher vapour pressure than the expected value. Examples: acetone + ethanol acetone + CS2; water + methanol; water + ethanol; CCl4 + toluene; CCl4 + CHCl3; acetone + benzene; CCl4 + CH3OH; Cyclohexane + ethanol | 1.Do not obey Raoult’s law. 2.?Hmix<0. Exothermic dissolution; heat is evolved. 3.?Vmix <0. Volume is decreased during dissolution. 4.pA < pA0XA; pB < pB0XB ∴ pA + pB < pA0XA + pB0XB 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 both components ‘A’ and ‘B’ is lowered showing lower vapour pressure than expected ideally. Examples: acetone + aniline; acetone + chloroform; CH3OH + CH3COOH; H2O + HNO3; Choloroform + diethyl ether, water + HCl; acetic acid + pyridine; chloroform + benzene. |
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Comparison Between Ideal and Non-ideal Solutions
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. 2.?Hmix = 0; neither is evolved nor absorbed during dissolution. 3.?Vmix = 0; total volume of solution is equal to sum of volumes of the components. 4.P = pA + pB = pA0XA + pB0XB i.e., pA = 5.A—A, A—B, B—B interactions should be same, i.e., ‘A’ and ‘B’ are identical in shape, size and character. 6. Escaping tendency of ‘A’ and ‘B’ should be same in pure liquids and in the solution. Examples: dilute solutions; benzene + toluence: n-hexane + n-heptane; chlorobenzene + bromobenzene; n-butyl chloride + n-butyl bromide. | 1.Do not obey Raoult’s law. 2.?Hmix>0. Endothermic dissolution; heat is absorbed. 3.?Vmix > 0. Volume is increased after dissolution.
4.pA > pA0XA; pB > pB0XB 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. 6. ‘A’ and B’ escape easily showing higher vapour pressure than the expected value. Examples: acetone + ethanol acetone + CS2; water + methanol; water + ethanol; CCl4 + toluene; CCl4 + CHCl3; acetone + benzene; CCl4 + CH3OH; Cyclohexane + ethanol | 1.Do not obey Raoult’s law. 2.?Hmix<0. Exothermic dissolution; heat is evolved. 3.?Vmix <0. Volume is decreased during dissolution. 4.pA < pA0XA; pB < pB0XB ∴ pA + pB < pA0XA + pB0XB 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 both components ‘A’ and ‘B’ is lowered showing lower vapour pressure than expected ideally. Examples: acetone + aniline; acetone + chloroform; CH3OH + CH3COOH; H2O + HNO3; Choloroform + diethyl ether, water + HCl; acetic acid + pyridine; chloroform + benzene. |
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Ideal and non-ideal solutions
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. neither heat is evolved nor absorbed during dissolution. | 2. Endothermic dissolution; heat is absorbed. | 2. Exothermic dissolution; heat is evolved. | |
3. total volume of solution is equal to sum of volumes of the components. | 3. Volume is increased after dissolution. | 3. Volume is decreased during dissolution. | |
4. i.e.,
| 4.
| 4.
| |
5. interactions should be same, i.e., 'A' and 'B' are identical in shape, size and character. | 5. attractive force should be weaker than and attractive forces. 'A' and 'B' have different shape, size and character. | 5. attractive force should be greater than and 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 +: water + methanol; water + ethanol; toluene; ; acetone + benzene; ; cyclohexane + ethanol | Examples: Acetone + aniline; acetone + chloroform; ;
chloroform + diethyl ether; water + HCl; acetic acid + pyridine; chloroform + benzene
| |
Graphical representation of ideal and non-ideal solutions
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Rault?s law : It state that the partial vapour pressure of each component of an ideal mixture liquid is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture ..
A non ideal solution is a solution that doesn't abide the rules of an ideal solution where the interaction between the molecules are identical to interaction between molecule of different components..
Hope it helps
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Rault?s law : It state that the partial vapour pressure of each component of an ideal mixture liquid is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture ..
A non ideal solution is a solution that doesn't abide the rules of an ideal solution where the interaction between the molecules are identical to interaction between molecule of different components..
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Ideal solns obeys raoults law whereas non ideal solns do not obeys raults law.
In ideal solns, enthalpy of mixing is zero whereas in non ideal solns entalpy of mixing is not equal to zero.
There is no change of vol. on mixing in case of ideal solns whereas there is change in vol. In case of non ideal solns
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A solution is called ideal solution if it obeys Raoult's law over a wide range of concentration at a specific temperature.
The enthalpy of mixing of the pure components to form the solution is zero and volume of mixing is also zero.
pA=(p?A)(xA) and pB=(p?B)(xB)
?Hmix=0, ?vmix=0,
The force of attraction between A-A and B-B is nearly equal to A-B.
Examples:
1. n-hexane
2. Ethyl bromide and Ethyl chloride,
3. Benzene and Toluene
4. Chlorebenzene and Bromobenzene
*Non-Ideal Solutions:*
A solution which does not obey Raoult's law for all concentration is called a non-ideal solution.
pA is not equal to (p?A)(xA) and pB is not equal to (p?B)(xB)
Also, ?Hmix and ?vmix are not equal to zero
The force of attraction between A-A and B-B is not equal to A-B.
Examples:
1. Water and Ethanol
2. Chloroform and Acetone
3. Ethanol and Cyclohexane
A non- ideal solution can show either positive or negative deviation from Raoult's law
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Here A.A=B.B=A.B interactiom
And
Non Ideal solutions are the solutions which do not obey raoult's law
Non ideal solutions are of two types
1-Positive deviation:
The type of solutions in which the calculated vapour pressure is more than the predicted one
In this type of solution A.A is weaker than A.A and B.B interaction
2-Negative deviation:
The type of solutions in which the calculated vapour pressure is less than the predicted one
In this type of solution A.A is stronger than A.A and B.B interaction
Hope it helps :)
Have a grt day!
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1)ideal solutions is that solution which obeys Raoult's law .there will be no change in volume on mixing 2 components. In ide solns.there is no change in enthalphy also.
2) non ideal solutions is that solution which doesnot obeys the Raoult law .there is change in volume and ethaphy when mixxing the 2 components...
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1)obey raoult's law.
2)the solute,solvent and solutions particles interaction are same.
3) solute and solvent molecules have almost similar structure and polarity.
4)volume change must be zero.
5) enthalpy changes must be zero.
Ex- n-heptane and n-hexane etc.
Non ideal are those which-
1)not obey raoult'law
2)the solute,solvent and solutions particles interaction are not same.
3) solute and solvent molecules not having similar structure and polarity.
4)volume change must not be zero.
5) enthalpy changes must not be zero.
Ex- water and HCl etc.
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1. Those solutions which obey's roults law over the entire range of concentration.
2. There is no enthalpy change when components of solution are mixing delta H mixing zero
3. Delta V mixing zero
NON- IDEAL
1. Doesn't obeys roults law .
2. Delta H mixing not zero.
3. Delta V mixing not zero.
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