Azeotropic Mixtures

Q.

What is meant by positive and negative deviations from Raoults law and how is the sign of Δ_solH related to positive and negative deviations from Raoults law?

Q. The mixture that forms a maximum boiling azeotrope is:

1. Water + Nitric acid
2. Ethanol + Water
   
3. Acetone + Carbon disulphide
4. Heptane + Octane

Q.

Which of the following is correct for the solution showing positive deviations from Raoults law?

1. $\mathrm{dV}=+\mathrm{ve}\mathrm{and}\mathrm{dH}=+\mathrm{ve}$

2. $\mathrm{dV}=+\mathrm{ve}\mathrm{and}\mathrm{dH}=-\mathrm{ve}$

3. $\mathrm{dV}=-\mathrm{ve}\mathrm{and}\mathrm{dH}=+\mathrm{ve}$

4. $\mathrm{dV}=-\mathrm{ve}\mathrm{and}\mathrm{dH}=-\mathrm{ve}$

Q.

Two solutions of glucose have osmotic pressure 1.5 atm and 2.5 atm. 1 litre of first solution is mixed with 2 litres of second solution. The osmotic pressure of resultant solution will be:

1. 21.6
2. 0.126
3. 2.16 atm
4. 0.216 atm

Q.

The pressure exerted by a mixture of 3.5 g of N₂ and 4g of H₂ contained in a 8.21 dm−3 flask at 27°C is

(1) 5.925 atm

(2) 6.375 atm

(3) 8.217 atm

(4) 3.291 atm

Q.

Question 23
If two liquids A and B form minimum boiling azeotrope at some specific composition then
(a) A-B interactions are stronger than those between A-A or B-B
(b) vapour pressure of solution increases because more number of molecules of liquids A and B can escape from the solution
(c) vapour pressure of solution decreases because less number of molecules of only one of the liquids escape from the solution
(d) A-B interactions are weaker than those between A-A or B-B

Q.

The boiling point of C₆H₆ , CH₃OH, C₆H₅NH₂ and C₆H₅NO₂ are 80⁰C, 65⁰C, 184⁰C and 212⁰C respectively. Which among them will show highest vapour pressure at room temperature?

Q.

Calculate the vapor pressure of an aqueous solution of 1 molal glucose solution at 100 degrees Celsius.

Q. At ${35}^{o}C$, the vapour pressure of $C{S}_{2}is512mmHg$ and that of acetone is $344mmHg$. A solution of $C{S}_2$ in acetone has a total vapour pressure of $600mmHg$. The false statement amongst the following is
(JEE MAIN 202)

1. A mixture of 100 mL $C{S}_2$ and 100 mL acetone has a volume < 200 mL
2. $C{S}_2$ and acetone are less attracted to each other than to themselves
3. Raoult's law is not obeyed by this system
4. Heat must be absorbed in order to produce the solution at $35°C$

Q. 69. among the following the solution which shows the lowest osmotic pressure is 0.010M NaCl, 0.05M CaCl2 , 0.04 M K3 [Fe(CN)6] , 0.03 M FeCl3

Q.

Question 25
On the basis of information given below mark the correct option. Information On adding acetone to methanol some of the hydrogen bonds between methanol molecules break.
(a) At specific composition methanol-acetone mixture will form minimum boiling azeotrope and will show positive deviation from Raoult's law
(b) At specific composition methanol-acetone mixture will form maximum boiling azeotrope and will show positive deviation from Raoult's law
(c) At specific composition methanol-acetone mixture will form minimum boiling azeotrope and will show negative deviation from Raoult's law
(d) At specific composition methanol-acetone mixture will form maximum boiling azeotrope and will show negative deviation from Raoult's law

Q. Volatile liquids A and B forming an azeotrope (at a particular temperature range) have vapour pressures of $280mm$ and $200mm$ respectively. If the mole fraction of A in the solution mixture is 0.3, and the mixture has a total vapour pressure of $300mm$.

Choose the correct statement(s) for the following mixture.

1. It forms a minimum boiling azeotrope.
2. It forms a maximum boiling azeotrope.
3. First minimum and then maximum boiling azeotrope is formed.
4. First maximum and then minimum boiling azeotrope is formed.

Q. $100mL$ of liquid 'A' and $50mL$ of liquid 'B' are mixed to form $138mL$ of solution. The given solution is a/an:

1. Ideal solution
2. Maximum boiling Azeotrope
3. Minimum boiling Azeotrope
4. None of the above

Q. The azeotropic mixture of water and $HCl$ bolis at ${108.5}^{\circ }C$. When this mixture is distilled, it is possible to obtain:

1. Pure $HCl$
2. Pure water
3. Neither pure $HCl$ nor water
4. Both pure $HCl$ and water

Q. Which of the following is/are true regarding maximum boiling azeotropes?

1. $\Delta H_{mix}<0$
2. Azeotropic mixture has higher vapour pressure as compared to vapour pressure of each component in pure state.
3. $\Delta S_{mix}>0$
4. $\Delta G_{mix}>0$

Q.

Which of the following does not show a positive deviation from Raoults Law?

1. Benzene-chloroform

2. Benzene-acetone

3. Benzene-ethanol

4. Benzene-carbon tetrachloride

Q.

Why ideal solutions do not form azeotropes?

Q. Which one of the following mixtures can be separated into pure components by fractional distillation

1. Water – nitric acid
2. Water – hydrochloric acid
3. Benzene – toluene
4. Water – ethyl alcohol

Q. Which of the following statement is true regarding azeotropic mixtures?

1. The mixture can be seperated by steam distillation
2. Azeotropic mixtures are formed by ideal solutions
3. The mixture can be seperated by fractional distillation
4. During boiling, composition of mixture remains constant

Q. 10. 1 m aq. solution of a salt shows elevation iin boiling point equal to 3 times of its K Determine() Freezing point of solution(ii) Osmotic pressure at 27 CKwater) 1.86 K kg mole-1

Q. Among the following the azeotropic mixture is:

1. $C{H}_{3}OH+CHC{l}_3$
2. $C_6{H}_{14}+C_7{H}_{16}$
3. $C_2{H}_{5}Br+C_2{H}_{5}Cl$
4. None of these

Q. Which of the following is/are correct graph(s) for a binary mixture of two volatile liquids which form a minimum boiling azeotrope?

1. 
2. 
3. 
4. Both (a) and (b)

Q. 18.what type of deviation from Raoults law is observed when two volatile liquids A and B on mixing produce cold solution explain with the help of a well labelled vapour pressure graph

Q. Which of the following is/are true regarding minimum boiling azeotropes?

1. $\Delta H_{mix}>0$
2. $\Delta V_{mix}<0$
3. $\Delta G_{mix}<0$
4. $\Delta S_{mix}>0$

Q. An azeotropic mixture of water $(B.P.373K)$ and nitric acid $(B.P.359K)$ is formed. Which of the following is true for the boiling point of mixture $T_{mix}$ ?

1. $T_{mix}<359K$
2. $T_{mix}>373K$
3. $359K<T_{mix}<373K$
4. Cannot be predicted

Q.

Question 36
Components of a binary mixture of two liquids A and B were being separated by distillation. After some time separation of components stopped and composition of vapour phase became same as that of liquid phase. Both the components started coming in the distiliate. Explain why this happened?

Q. The half life period of the following first order reaction is (\log 3 = 0.4771) C2H4O2(g) → CH4(g) + CO2(g) Given that initial pressure of C2H4O2(g) is 84 mm and total pressure at the end of 16 minutes is 110 mm (\log 3 = 0.4771)

Q. Which of the following graph is obtained for mixture of these two binary volatile liquids :
$HN{O}_3\left(68\%\right)+H_{2}O\left(32\%\right)$

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

Q. Which has lowest osmotic pressure at same temperature?(1) 100 ml of 1 M urea(2) 400 ml of 0.5 M KCI(3) 200 ml of 0.5 M glucose(4) 300 ml of 0.25 M K3PO4

Q. The plot of $P_T$ vs $y_A$ at constant temperature in the pressure composition diagram is
$P_A\to \text{Total pressure}$
$y_A\to \text{Mole fraction of A in vapour phase}$

1. 
2. 
3. 
4.