LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

DB 12

FIFTH SEMESTER – November 2008

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 07-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART A

Answer ALL the questions                                                                        10X2=20

 

1. What is condensed phase rule equation.
2. Find out the number of components in           (i) CaCO₃(s) CaO(s)+ CO₂(g)

(ii)NH₄Cl(s)  NH₃(g)  + HCl(g)

1. Define vapour pressure of a liquid?
2. Give two limitations of Nernst distribution law.
3. Distinguish between order and molecularity.
4. Give an example each for first order and zero order reactions
5. How does ionic strength affect the rate of a reaction?
6. What is adsorption?
7. Cite an example for homogeneous and heterogeneous catalysis.
8. Mention the characteristic features of enzyme catalysis.

 

PART B

Answer any EIGHT questions                                                                     8X5=40

 

1. The melting point of ice is higher than that of ice mixed with salt. Why?
2. Discuss the salient features of the phase diagram of Pb-Ag system
3. How will you obtain absolute alcohol from rectified spirit?
4. 1.1 g of a protein were dissolved in 100 mL of solution. The osmotic pressure at 25˚C was measured as 1150 Nm^-2. What is the molar mass of the protein?
5. Describe any one method of determination of order of a reaction.
6. Obtain the integrated rate equation for a second order reaction 2Aproducts.
7. Compare and contrast absolute reaction rate theory and collision theory.
8. A first order reaction has a half life of 30 minutes at 27˚C. Its rate constant at 47˚C is 1.15X10^-3 sec^-1. Calculate the energy of activation.
9. Derive Langmuir’s adsorption isotherm equation.
10. Explain kinetics of bimolecular surface reactions with one example.
11. Discuss the significance of     (i) Raoult’s law

(ii) Henry’s law

1. Enumerate the steps involved in thermal dissociation of acetaldehyde.

 

 

PART C

Answer any FOUR questions                                           4X10=40

 

23. Derive Michaelis Menten equation for the kinetics of enzyme catalysis.
24. Explain Lindemann hypothesis with reference to the kinetics of unimolecular reactions.
25. (a) At 27°C in the presence of a catalyst, the activation energy of a reaction is lowered by 2 k cal. Calculate by how many times the rate of the reaction increases by the presence of this catalyst.            (5)

(b) Differentiate physisorption from Chemisorption.                        (5)

1. (a) Draw the phase diagram of water system and explain.                 (5)

(b) Derive Nernst distribution law                                                      (5)

1. (a) Discuss the principle and experimental method involved in fractional

Distillation of a binary liquid mixture.

(b) Derive phase rule equation                                                            (5)

1. Derive thermodynamically the relation between elevation in boiling point and morality.

 

 

 

       LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

WD 25A

FIFTH SEMESTER – April 2009

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date & Time: 24/04/2009 / 1:00 – 4:00   Dept. No.                                                      Max. : 100 Marks

 

 

 

PART – A

Answer ALL questions                                                                                 (10 X 2 = 20)

 

• Identify the number of phases and components at equilibrium

CaCO_3(s)                       CaO_(s)   +   CO_2(g)

2)      Apply phase rule equation at the triple point of water.

3)      What are isotonic solutions?

4)       A solution of 0.1 M NaCℓ aqueous solution has a boiling point of 101.04^o C. What will be the boiling point of 0.2 M urea solution Kb = 0.52K kg mol ^-1?

5)      Define rate constant of a reaction.

6)      What is a zero order reaction?

7)      Calculate the ionic strength of 0.1 m BaCℓ₂ solution at 25^o C

8)      Enzyme catalysis decelerates at high temperatures.  Why?

9)      What is Wilkinson’s catalyst?

10) Distinguish between adsorption and absorption.

PART – B

Answer ANY EIGHT questions only                                                                      (8 X 5 = 40)

 

• Draw and describe phase diagram of Pb – Ag system

12)  Explain the phase behavior of a three component system.

13)  What is an azeotrope?  Explain azeotropic distillation with an example.

14)  Derive Nernst Distribution law.

15)  What are chain reactions. Explain with an example.

16)  There is a first order dependence on concentration of KI and K₂S₂O₈.  If the initial concentration of K₂S₂O₈ is ‘a’ moles dm^-3 and KI is ‘2a’ moles dm^-3.   Derive the expression for the rate constant of the reaction.

17)  Explain the terms order, molecularity and stoichiometry of a reaction with a suitable example.

18)  Explain the kinetics of parallel reactions with an example.

19)  State steady state approximation.  Illustrate with an example

20)  The specific rate of decomposition of HI at 556 K & 781 K are 3.517 X10^-7 dm³ mol^-1 s^-1 and     3.954 X 10^-2 dm³ mol^-1 s^-1 respectively.  Calculate energy of activation in cal mol^-1 and Arrhenius pre-exponential factor A in dm³ mol^-1 s^-1.

 

 

21)  Explain the kinetics of acid catalysed ester hydrolysis.  How the order with respect to each reactant is determined.

22)   Distinguish between physisorption and chemisorption.

 

PART C

Answer ANY FOUR questions only                                                                       (4 X 10 = 40)

 

23)  Draw the phase diagram of FeCℓ₃ – water system and apply phase rule.

24)  Derive the relation between elevation of boiling point and morality of the solution, thermodynamically.

25)  Explain any two of the following:                                                                                                        a) Phase diagram of partially miscible liquid pair exhibiting both UCST & LCST                                  b) Application of distribution law to KI  +  I₂              KI₃ equilibrium                                               c) Raoults law and its deviations                                                                                                        d) Application of Clapeyron equation

26)  A) Describe Van’t Hoff differential method of determination of order of a reaction                                              B) Explain one mechanism of bimolecular surface reaction.

27)  Discuss the kinetics enzyme catalysis as propounded by Michaelis Menton in detail.

How the rate constants of individual steps are evaluated.

28)  State the postulates of Langumir adsorption isotherm and hence derive the equation and explain.

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2010

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 03-11-10                     Dept. No.                                                 Max. : 100 Marks

Time : 9:00 – 12:00

 

PART-A

Answer ALL questions                                                                                            (10 X 2 = 20 marks)

 

• Write the expression for degree of freedom.
• Define Eutectic temperature.
• State Raoult’s law.
• State Nernst distribution law.
• Write the chemical equation for the oxidation of iodide by persulphate. What is the

overall order of the reaction.

• Define specific rate. Comment on its unit.
• A radio active element undergoes nuclear disintegration. What type of complex

reaction is it?

• Predict the effect of added KNO₃ on the rate of oxidation of iodide by persulphate.
• Write the general steps involved in a chain reaction.
• Distinguish between adsorbent and adsorbate.

PART-B

 

Answer any EIGHT questions                                                                                  (8 X 5 = 40 marks)

 

• Draw the phase diagram of sulphur system and apply phase rule to it.
• Magnesium and Zinc form a stable compound with the composition of MgZn₂ having congruent melting point.  Draw the phase diagram for the system and apply phase rule to it.
• (a) Define cryoscopic constant and give its significance.                                    (2)

 

(b) 0.001 Kg of a solute  dissolved in 0.1 Kg of solvent having cryoscopic constant 5.0 K Kg

mole^-1  gave a depression in freezing point as 0.2 K.  Calculate the molecular mass of

the solute.                                                                                                                                (3)

 

• What would be the vapour pressure of 0.5molal solution of urea in water at 298 K. (Given

that vapour pressure of pure water at 298 K is 3173Pa).

 

• Why acid catalysed hydrolysis of ester follows pseudo first order kinetics? Derive the

expression for the rate constant of this reaction.

 

• Describe Van’t Hoff differential method of determining the order of a reaction.

 

• (a) What is critical solution temperature? Explain with an example.                                  (2)

(b) How CST of phenol-water system vary with added NaCℓ ?                                              (3)

 

• In the reaction of hydrogen with bromine under thermal condition, the following observations are made:

1. The rate of the reaction is having first order dependence on H₂ and fractional order dependence on Br₂
2. Product formed, HBr is found to retard the reaction.
3. Presence of radicals is proved.
4. Addition of Br₂ is found to reduce the inhibiting nature of HBr.
5. Overall rate expression for the reaction is rate = {k[H₂][Br₂]^1/2}  {k’ + k”[HBr]}

Propose a probable mechanism for the reaction to explain the above observations.

 

• List any five factors that affect the rate of a chemical reaction.
• Explain Lindemann hypothesis of unimolecular reactions.
• Explain the steps involved in a heterogeneous catalysed reaction.
• Discuss the kinetics of enzyme catalysed reactions.

PART-C

 

Answer any FOUR questions                                                                                  (4 X 10 = 40 marks

 

• Ferric Chloride when added to water, forms four different types of hydrates having definite congruent melting points. Draw a phase diagram depicting the observed phenomenon and apply phase rule to the system.
• (a) Explain the principle of Pattinsons process.                                      (5)

(b) Explain the principle of fractional distillation.                                                                                    (5)

• When 1 liltre of an aqueous solution containing 5g of a solute is shaken with 50 mL of ether, it is found that 0.84 g of solute passes into ether. How much of solute will be left unextracted if same aqueous solution is shaken with second installment of 50 mL ether.  What would be left behind if there was only one extraction with 100 mL of ether.
• (a) Derive the expression for the rate constant of of a second order reaction

2 A products                                                                                                                             (5)

(b) Define half life of a reaction.  How half life measurements can be used to determine the

order of the reaction.                                                                                                                  (5)

27) Give the postulates of collision theory and deduce the expression for the rate constant of

a bimolecular reaction.                                                                                                          (4+6)

28) Derive Langmuir adsorption isotherm equation and explain.                                                     (5+5)

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2011

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 19-04-2011              Dept. No.                                          Max. : 100 Marks

Time : 1:00 – 4:00

 

SECTION –A

Answer ALL the questions                                                                                          (10 x 2 = 20 marks)

1. The fusion curve of ice in the phase diagram of water is inclined towards the pressure axis. Account for this phenomena.
2. State phase rule and mention the terms involved in it.
3. Define zero order reaction. Give an example.
4. Bring out the differences between order and molecularity of a reaction.
5. “Addition of a non-volatile solute lowers the vapour pressure of a solution” – Offer a theoretical explanation for this statement.
6. What do you mean by abnormal Colligative properties?
7. State the steps that are involved in the thermal decomposition of acetaldehyde.
8. Explain how ionic strength affects the rate of a reaction.
9. What is a pseudo order reaction?
10. Define the term ‘Adsorption’.

SECTION –B

Answer ANY EIGHT questions                                                                                (8 x5 = 40 MARKS)

11. Apply phase rule to sulphur system.
12. Explain phase rule to lead-silver system and discuss the desilverisation of lead from this system.
13. Define osmotic pressure. Derive a relationship between osmotic pressure and lowering of vapour-pressure.
14. If a solution containing 6g of triphenyl methane(mol.wt=244) in 1000g of benzene is cooled to 22°C below the freezing point of benzene, how much solvent will crystallize out ?

( K_f = 5.1 K kg mol^-1)

15. Derive the expression for the rate constant for the reaction 2A → products.
16. Why do the rates of reactions in general have a large temperature co-efficient?
17. The specific reaction rate of a reaction is 1 x 10^-3 min^-1 at 27°C and 2×10^-3 min^-1 at 37°C. Calculate the energy of activation of this reaction and its specific reaction rate at 47°C.
18. Explain i) consecutive reaction ii) parallel reaction with one example for each.
19. Explain the theory of absolute reaction rate and show how it is superior to other theories.

 

 

20. Derive Nernst distribution law and state its limitations.
21. State and explain the factors that affect the rate of enzyme catalysis.
22. What are Wilkinson’s catalysts? Explain its catalytic action in reactions.

 

SECTION –C

Answer any FOUR the questions                                                                               (4 x 10 = 40 MARKS)

23. Draw and explain the phase diagram of FeCl₃-H₂O system.
24. (a) How are volumetry, monometry, useful in studying the reaction kinetics. Give one example for each.

(b) Explain the mechanism of S_N1 reaction.

25. Explain Lindemann’s steady state principle. Show that the reaction is first order at high concentration and second order at low concentration. Derive the relevant expression.
26. (a) State Raoult’s law. Explain the different types of deviation from this law.

(b) Derive Clausius-Clapeyron equation and state any one of its applications.

27. Explain with a suitable diagram that lowering of vapor pressure is the cause for change in boiling point and freezing poing of a solution.
28. State the postulates of Langmuir’s adsorption equation and discuss the effects at very low and high pressures.  Derive the equation.

 

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – APRIL 2012

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 30-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

 

Answer ALL questions:                                                                                      (10 x 2 = 20 marks)

 

1. Define congruent melting point.
2. State phase rule and mention the terms involved in it.
3. What are isotonic solutions?
4. What do you mean by abnormal Colligative properties?
5. What are zero order reactions? Give an example.
6. Bring out the differences between order and molecularity of a reaction.
7. State the steps that are involved in the thermal docomposition of acetaldehyde.
8. Explain how ionic strength affects the rate of a reaction in solution.
9. What is heterogenous catalysis?
10. Define the term Adsorption.

PART – B

Answer any EIGHT questions:                                                                           (8 x 5 = 40 marks)

 

11. Apply phase rule to water system. Draw the phase diagram of it.
12. Explain phase rule to lead-silver system and discuss the desilverisation of lead from this

system.

13. State and explain Raoult’s law.
14. The molar heat of vaporization of water at 100^oC is 40.585 kJ mol^-1. At what temperature

will a solution containing 5.60 g of glucose per 1000 g of water boil?

15. What are azeotropes? Explain.
16. Derive the expression for the rate constant for the reaction 2A -> products.
17. Calculate the activation energy of a reaction whose rate constant is tripled by a 10^oC rise in

temperature  from the initial temperature of 27^oC.

18. Explain the kinetics of parallel reaction with one example.
19. Explain the theory of absolute reaction rate and show how it is superior to other theories.
20. Explain the kinetics of acid catalysed ester hydrolysis.
21. State and explain the factors that affect the rate of enzyme catalysis.
22. What are Wilkinson’s catalysts? Explain its catalytic action in reactions.

PART – C

Answer any FOUR questions:                                                                          (4 x 10 = 40 marks)

 

23. Draw and explain the phase diagram of FeCl₃-H₂O system.

 

24. (a) Derive Clausius-Clapeyron equation and state any one of its applications.

(b) Explain partially miscible binary systems with suitable examples.

 

25. (a) Derive Nernst distribution law and state its limitations.

(b) Discuss on steam distillation.

 

26. (a) Explain the differential method of determination of order of a reaction.

(b) Explain the effect of solvent on the rate on S_N2 reaction.

 

27. (a) Explain Lindemann’s steady state principle.

(b) State the postulates of Langmuir’s adsorption equation and derive the equation.

 

28. Discuss the kinetics of enzyme catalysis with Michaelis – Menton mechanism. How are the

rate constants evaluated?

 

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2012

CH 5507 – PHASE EQUILIBRIA AND KINETICS

 

 

 

Date : 06/11/2012             Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

 

Answer ALL questions:                                                                                           (10 x 2 = 20 marks)

 

1. Define the term phase.
2. What is congruent melting point?
3. State Raoults’ law.
4. In the distillation of liquid L by steam, the mixture boils at 99^oC at a pressure 760 mm. At this

temperature the vapour pressure of water is 733 mm.   The composition of distillate is H₂O; L = 4:1.

Calculate the molecular weight of liquid L from this data.

5. Define the order of a reaction.
6. What are pseudo first order reactions? Give an example.
7. Write the Arrhenius equation and define the terms involved in it.
8. What are parallel reactions? Give an example.
9. What is acid-base catalysis?
10. What is Wilkinson’s catalyst? Write one application of it.

 

PART – B

 

Answer any EIGHT questions:                                                                               (8 x 5 = 40 marks)

 

11. Derive Clausius – Clapeyron equation. Give its applications.
12. Discuss the salient features of the phase diagram of Lead-Silver system.
13. Explain critical solution temperature. What is the effect of addition of solute on it?
14. Discuss Van’t Hoffs’ theory of dilute solutions.
15. A solution containing 3.975 g of sulphur in 100 g of CS₂ boils at 319.67 K. The boiling point of pure

CS₂  is 319.30 K  and ΔH_vap = 27.78 kJ mol^-1.   Calculate the molecular formula of sulphur in carbon

disulphide.

16. Derive the rate constant for First order reaction.
17. A second order reaction in which the initial concentrations of both the reactants are equal (i.e. a = b =

1 mol dm^-3) proceeds to an extent of 25% in 5 hrs.   How long will it take for the reaction to be

completed to the extent of 60%?

18. Explain the reversible reaction with an example.

 

19. Discuss the ARRT in detail.
20. Explain the steps involved in the thermal dissociation of acetaldehyde reaction.
21. Discuss the homogenous catalysis with an example.
22. Explain the Langmuir’s unimolecular adsorption isotherm.

 

PART – C

 

Answer ANY FOUR questions:                                                                              (4 x 10 = 40 marks)

 

23. Explain and draw the phase diagram of Ferric – Chloride – water system.

Apply the relevant phase rule equation.

 

24. Write notes on any TWO:
25. a) Solvent Extraction
26. b) Phase diagram of three component system
27. c) Nernst distribution law
28. d) Phase diagram of Sulphur system.

 

25. Derive thermodynamically the relationship between elevation in boiling point of a solution and its

molality.

 

26. Explain any THREE methods of determining order of a reaction.

 

27. Explain the collision theory of bimolecular and unimolecular reactions.

 

28. Derive Michaelis – Menton equation and discuss the kinetics of enzyme catalysis.

 

 

 

 

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