Question

100 ml of liquid A and 25 mL of liquid B are mixed to form a formal solution of volume 125mL. then the solution is ___________.
A.Ideal
B.Non-ideal with positive deviation
C.Non-ideal with negative deviation
D.Cannot be predicted

Answer 1

Hint: An ideal solution or ideal mixture is a solution in which the gas phase exhibits thermodynamics properties analogous to those of a mixture of ideal gas.

Complete step by step answer:
An ideal solution is one in which the molecules attract with one another with equal force irrespective of their nature.
Thus, a solution composed of two components A and B will be an ideal solution if the forces between A and A, B and B should be the same.
An ideal solution possesses the following characteristics:
-Volume change of mixing should be zero.
$\Delta {V_{mixing}} = 0$
${V_{solvent}} + {V_{solute}} = {V_{solution}}$
-Heat change on mixing should be zero.
$\Delta {H_{mixing}} = 0$
(Heat is neither absorbed nor evolved)
-There should be no chemical reaction between solvent and solute like
Solvent + Solute$ \to $Solution
${H_2}O + N{H_3} \to N{H_4}OH$
${H_2}O + C{O_2} \to {H_2}C{O_3}$
-Non ideal ${H_2}O + CaO \to Ca{(OH)_2}$
-Solute molecules should not dissociate in the ideal solution.
-Solute molecules should not be associated with the ideal solution.
-Ideal solutions must obey Raoult’s law at all concentrations.
The following are some of the binary mixtures which show properties of ideal solutions.
-Benzene and Toluene
-Carbon Tetrachloride and Silicon Tetrachloride
-N-hexane and n-heptane
-Ethylene dibromide and ethylene trichloride
We know that according to the question, the volume is zero. So the solution is ideal.
$\Delta {V_{mixing}} = 0$
${V_{solvent}} + {V_{solute}} = {V_{solution}}$

Hence, the correct option is (A).

Note:
We know that for ideal solution $\Delta {H_{mixing}} = 0$and $\Delta {V_{mixing}} = 0$ but $\Delta {S_{mix}} \ne 0$for ideal solution.
Because, theoretically, entropy should increase while mixing two ideal mixtures.
(according to second law of thermodynamics)