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प्रश्न
What role does the molecular interaction play in a solution of alcohol and water?
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उत्तर १
In pure alcohol and water, the molecules are held tightly by a strong hydrogen bond. The interaction between the molecules of alcohol and water is weaker than the alcohol-alcohol and water-water interactions. As a result, when alcohol and water are mixed, the intermolecular interactions become weaker and the molecules can easily escape. This increases the vapour pressure of the solution, which in turn lowers the boiling point of the resulting solution.
उत्तर २
Alcohol and water both have a strong tendency to form intermolecular hydrogen bonds. On mixing the two, a solution is formed as a result of the formation of H-bonds between alcohol and H2O molecules, but these interactions are weaker and less extensive than those in pure H2O. Thus, they show a positive deviation from ideal behaviour. As a result of this, the solution of alcohol and water will have a higher vapour pressure and a lower boiling point than that of water and alcohol.
संबंधित प्रश्न
Vapour pressure of pure acetone and chloroform at 328 K are 741.8 mm Hg and 632.8 mm Hg respectively. Assuming that they form ideal solution over the entire range of composition, plot `p_"total"`, `p_"chloroform"` and `p_"acetone"` as a function of `chi_"acetone"`. The experimental data observed for different compositions of mixtures is:
| `bb(100 xx chi_"acetone")` | `bb(P_"acetone"//"mm Hg")` | `bb(p_"chloroform"//"mm Hg")` |
| 0 | 0 | 632.8 |
| 11.8 | 54.9 | 548.1 |
| 23.4 | 110.1 | 469.4 |
| 36 | 202.4 | 359.7 |
| 50.8 | 322.7 | 257.7 |
| 58.2 | 405.9 | 193.6 |
| 64.5 | 454.1 | 161.2 |
| 72.1 | 521.1 | 120.7 |
Plot this data also on the same graph paper. Indicate whether it has a positive or negative deviation from the ideal solution.
What type of intermolecular attractive interaction exists in the pair of methanol and acetone?
Fill in the blanks by choosing the appropriate word/words from those given in the brackets:
Ideal solutions obey ………. law and they …………. form azeotropic mixtures.
(Henry’s, aldol condensation, absence, do not, ohm, Raoult’s, increases, common ion effect, easily, three, solubility product, ohm-1, two, four, ohm-1, cm2, Cannizzaro, ohm-1 cm-1, zero, decreases, presence)
The mass of a non – volatile solute (molar mass 80 g mol-1) should be dissolved in 92g of toluene to reduce its vapour pressure to 90% ______.
Assertion: An ideal solution obeys Raoults Law.
Reason: In an ideal solution, solvent – solvent as well as solute – solute interactions are similar to solute-solvent interactions.
The observed depression in the freezing point of water for a particular solution is 0.093°C calculate the concentration of the solution in molality. Given that molal depression constant for water is 1.86 K Kg mol-1.
For ideal solution the volume of mixing of the pure components to form the solution is ____________.
Which relationship is not correct?
If two liquids A and B form minimum boiling azeotrope at some specific composition then ______.
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Assertion: When a solution is separated from the pure solvent by a semipermeable membrane, the solvent molecules pass through it from pure solvent side to the solution side.
Reason: Diffusion of solvent occurs from a region of high concentration solution to a region of low concentration solution.
Upon increase in pressure for dissociation N2O4 into NO2, equilibrium shift towards
Dissociation constant and molar conductance of an acetic acid solution are 1.78 × 10–5 mol L–1 and 48.15 S cm–2 mol–1 respectively. The conductivity of the solution is (considering molar conductance at infinite dilution is 390.5 S cm–2 mol–1)
How many times more hydrogen ions in a solution with a pH of 3 than in a solution with a pH of 6
The pH of a solution of hydrochloric acid is 1.5. Calculate the concentration of the acid.
On increase in pressure for dissociation ofN2O4 into NO2, equilibrium shift towards
Which of the following gave the idea of a nucleus of the atom?
What type of deviation from Roult’s Law is expected when phenol and aniline are mixed with each other? What change in the net volume of the mixture is expected? Graphically represent the deviation.
