Ideal Solutions

Q.

What role does the molecular interaction play in a solution of alcohol and water?

Q.

QUESTION 2.10

What role does the molecular interaction play in a solution of alcohol and water?

Q. The vapour pressure of two pure liquids $\text{A}$ and $\text{B}$, that forms an ideal solution, are 100 and $900\text{torr}$ respectively at temperature $\text{T}$. This liquid solution of $\text{A}$ and $\text{B}$ is composed of 1 mole of $\text{A}$ and 1 mole of $\text{B}$. What will be the pressure, when 1 mole of this mixture has been vaporized?

1. $800\text{torr}$
2. $500\text{torr}$
3. $300\text{torr}$
4. None of these

Q.

Which of the following shows a negative deviation from Raoults law?

1. ${\mathrm{C}}_6{\mathrm{H}}_6\mathrm{and}{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

2. ${\mathrm{C}}_6{\mathrm{H}}_6\mathrm{and}{\mathrm{CCl}}_4$

3. ${\mathrm{CHCl}}_3$ and Acetone

4. ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3\mathrm{and}{\mathrm{C}}_6{\mathrm{H}}_6$

Q. Molarity, molality normality , formality

Q. Two liquids X and Y form an ideal solution. At 300 K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm of Hg. At the same temp, if 1 mole of Y is further added to this solution, vapour prossure of the solution increases by 10 mm Hg. Vapour pressure of X and Y in their pure state will be, respectively:

1. 500 and 600
2. 400 and 600
3. 200 and 300
4. 300 and 400

Q.

Which has lowest freezing point at 1 atm?

1)0.1M NaCl solution

2)0.1M BaCl2 solution

3)0.1M sugar solution

4)0.1M FeCl3 solution

Q. Two liquids $\text{A}$ and $\text{B}$ have ${P^{\circ }}_A:{P^{\circ }}_B=1:3$ at a certain temperature. If the mole fraction ratio of $x_A:x_B=1:3$, the mole fraction of $\text{A}$ in vapour in equilibrium with the solution at a given temperature is

1. 0.1
2. 0.2
3. 0.5
4. 1

Q. For the process
$H_{2}O\left(l\right)\rightleftharpoons H_{2}O\left(g\right)(1atm,373K),$ the correct set of thermodynamic parameters is

1. $△G=0,△S=+ve$
2. $△G=0,△S=-ve$
3. $△G=+ve,△S=0$
4. $△G=-ve,△S=+ve$

Q.

Maximum deviation from ideal gas is expected from

1. ${\mathrm{H}}_2$

2. ${\mathrm{N}}_2$

3. ${\mathrm{CH}}_4$

4. ${\mathrm{NH}}_3\left(\mathrm{g}\right)$

Q. 14. Calculate the molarity of a solution of CaCl2 if on chemical analysis it is found that 500 ml of CaCl2 solution contains 1.505*10 is to power 23 Cl- ion

Q. Which of the following is not an example of an Ideal solution?

1. Benzene + Toluene
2. n-Hexane + n-Heptane
3. Ethyl alcohol + Water
4. Ethyl bromide + Ethyl chloride

Q. Which of the following 0.1 M aqueous solutions will have the lowest freezing point?

1. Potassium sulphate
2. Glucose
3. Sodium Chloride
4. Urea

Q. What is the difference between primary standard and secondary standard solutions?

Q. Which of the following is true for a non-ideal solution showing negative deviation from Raoult’s law?

1. ${\Delta }_{\text{mix}}H>0$
2. ${\Delta }_{\text{mix}}H<0$
3. ${\Delta }_{\text{mix}}V=0$
4. ${\Delta }_{\text{mix}}V>0$

Q.

If 50mL of 0.1M NaCl and 50mL of 0.1M BaCl₂ are mixed, molarity of chloride ion in the resulting solution will be

1. 0.2M
2. 0.3M
3. 0.15M
4. 0.1M

Q.

Explain the surface tension phenomenon with examples.

Q. Choose the correct statement regarding vapour pressure:

1. It is calculated for an open vessel
2. It does not depend upon surface area
3. More the volume of container in which the liquid is present , more is the vapour pressure.
4. (a) and (b) above.

Q. The specific gravity of a HNO_3 solution is 1.42 and it is 70% w/w. The molar concentration of HNO_3 is (1) 15.8 (2) 31.6 (3) 11.1 (4) 14.2

Q.

QUESTION 2.37

Vapour pressures 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 $p_{acetone}$. The experimental data observed for different compoisition of mixture is:

$\begin{array}{ccccccccc}100x_{acetone}& 0& 11.8& 23.4& 36.0& 50.8& 58.2& 64.5& 72.1\\ p_{acetone}/mmHg& 0& 54.9& 110.1& 202.4& 322.7& 405.9& 454.1& 521.1\\ p_{chloroform}/mmHg& 632.8& 548.1& 469.4& 359.7& 257.7& 193.6& 161.2& 120.7\end{array}$

Plot this data also on the same graph paper. Indicate whether it has positive deviation or negative deviation from the ideal solution.

Q.

0.7 g of Na₂Co₃ .XH₂O were dissolved in water and the volume was made to 100mL , 20 mL of this solution required 19.8 mL of N/10 HCl for complete neutralisation, the value of 'x' is

A) 7

B) 3

C) 2

D) 5

Q.

Which compounds show negative deviation from Raoults law?

Q. calculate the volume of water to be added to 400 ml of seminormal HCL solution to make it decinormal

Q.

In a solution with positive deviation vapour pressure of solution is greater than vapour pressure of pure solvent. Explain.

Q. Which of the following is true regarding ideal solutions?

1. ${\Delta }_{\text{mix}}G>0$
2. ${\Delta }_{\text{mix}}V>0$
3. ${\Delta }_{\text{mix}}H=0$
4. ${\Delta }_{\text{mix}}S=0$

Q. 20. What approximate volume of 0.40 M Ba(OH)2 must be added to 50 ml of 0.30 M NaOH to get a solution in which the molarity of the OH- ions is 0.50 M ?

Q. Consider a binary mixture of volatile liquids.
For which of the following graph , solvent-solute interaction equal to that of solvent-solvent and the solute-solute interactions?

1. 
2. 
3. 
4. None of the above

Q. 14.The molar mass of solute sodium hydroxide obtained from measurement of osmotic pressure of its aqueous solution at 27c is 25g/mol. Therefore its ionization percentage in this solution A)75 B)60 C)80 D)70

Q. 71 Sea water is found to contain 5.85% NaCl and 9.5% MgCl2 by weight of solution. Calculate its normal boiling point assuming 80% ionisation for NaCl and 50% ionisation of MgCl2. Kb for water = 0.51 kg K / mol (i) Tb = 102.3^°C (ii) Tb = 105.3 K (iii) Tb = 110^°C (iv) Tb = 112 K

Q. What is the vapour pressure of benzene at ${25}^{\circ }C$ ? The normal boiling point of benzene is ${80}^{\circ }C$ and its molar heat of vaporization is $30.8kJ/mol$. [$e^{-1.94}=0.14$]

1. $0.39atm$
2. $0.14atm$
3. $1.94atm$
4. $0.45atm$