Advertisements
Advertisements
Questions
Distinguish between ideal and non-ideal solutions.
Using the Raoult’s law, how would you distinguish between ideal and non-ideal solutions?
Mention the main points of difference between ideal and non ideal solutions.
Mention the main points of difference between ideal and non ideal (both showing positive as well as negative deviations) solutions. Give at least two examples of each type.
Advertisements
Solution 1
| Ideal solutions | Non-ideal solutions | |
| 1. | Ideal solutions obey Raoult’s law over the entire range of concentrations. | Nonideal solutions do not obey Raoult’s law over the entire range of concentrations. |
| 2. | The vapour pressure of an ideal solution always lies between the vapour pressures of pure components. | The vapour pressures of these solutions can be higher or lower than those of pure components. |
| 3. | Solvent-solute, solute-solute and solvent-solvent molecular interactions are comparable. | Solute-solvent intermolecular attractions may be weaker or stronger than those between solute-solute molecules and solvent-solvent molecules. |
| 4. | e.g. Benzene + toluene, n-Hexane + n-Heptane | e.g. Ethanol + acetone Carbon disulphide + acetone Phenol + aniline Chloroform + acetone, Acetone + ethanol (CH3COCH3 + C2H5OH) |
Solution 2
| Sr. No. | Ideal solution | Non-ideal solutions | |
| Solutions showing positive deviation | Solutions showing negative deviations | ||
| 1. | A-B molecular interaction forces are similar to A-A or B-B molecular interaction forces. | A-B molecular interaction forces are weaker than A-A or B-B molecular interaction forces. | A-B molecular interaction forces are stronger than A-A or B-B molecular interaction forces. |
| 2. | pA = pA° χA; pB = pB° χB |
pA > pA° χA; pB > pB° χB |
pA < pA° χA; pB < pB° χB |
| 3. | No heat is evolved or absorbed during dissolution. | Dissolution is endothermic. | Dissolution is exothermic. |
| 4. | `Delta H_"mixing" = 0` | `Delta H_"mixing" > 0` | `Delta H_"mixing" < 0` |
| 5. | `Delta V_"mixing" = 0` | `Delta V_"mixing" > 0` | `Delta V_"mixing" < 0` |
| 6. | Do not form azeotropic mixtures. | Form minimum boiling azeotropic mixtures. | Form maximum boiling azeotropic mixtures. |
Notes
Students should refer to the answer according to their questions.
APPEARS IN
RELATED QUESTIONS
Choose the most correct option.
The vapour pressure of a solution containing 2 moles of a solute in 2 moles of water (vapour pressure of pure water = 24 mm Hg) is ______.
Choose the most correct option.
Vapour pressure of a solution is _______.
The vapour pressure of water at 20°C is 17 mm Hg. What is the vapour pressure of solution containing 2.8 g urea in 50 g of water?
A mixture of benzene and toluene contains 30% by mass of toluene. At 30°C, vapour pressure of pure toluene is 36.7 mm Hg and that of pure benzene is 118.2 mm Hg. Assuming that the two liquids form ideal solutions, calculate the total pressure and partial pressure of each constituent above the solution at 30°C.
What type of solutions exhibit positive deviations from Raoult’s law?
With the help of vapour pressure-temperature curves for solution and solvent, explain why boiling point of solvent is elevated when a nonvolatile solute is dissolved into it.
The vapour pressure of a pure solvent at a certain temperature is 0.0227 bar. What is the vapour pressure of a solution containing 6 g of solute (M = 60 g/mol) in 50 g of solvent?
Which of the following statements is INCORRECT?
Which of the following metals is refined by vapour phase refining in Mond process?
9 gram anhydrous oxalic acid (mol. wt. = 90) was dissolved in 9.9 moles of water. If vapour pressure of pure water is pf the vapour pressure of solution is ______.
5.0 g of sodium hydroxide (molar mass 40 g mol-1) is dissolved in little quantity of water and the solution is diluted upto 100 mL. What is the molarity of the resulting solution?
A solution of acetone in ethanol ______.
18 g of glucose (C6H12O6) is added to 178.2 g of water. The vapour pressure of water for this aqueous solution at l00°C is ______.
Total vapour pressure of a mixture of 1 mole A`("p"_"A"^circ = 150 " torr")` and 2 mole B`("p"_"B"^circ = 240 " torr")` is 200 mm. In this case, ______.
The vapour pressures of two liquids A and B are 80 mmHg and 60 mm Hg respectively at 25°C. What is the vapour pressure of the solution obtained by mixing 3 moles of A and 2 moles of B?
A solution having highest vapour pressure is ______.
Explain the variation of vapour pressures with mole fractions of binary solutions of two volatile liquids forming ideal solutions.
Write the relationship between mole fraction of solvent and vapour pressure of solution.
A mixture of two liquids A and B have vapour pressures 3.4 × 104 Mn-2 and 5.2 × 104 Nm-2. If the mole fraction of A is 0.85, find the vapour pressure of the solution.
Which one of the following is not correct for an ideal solution?
