Calcutta University (BSc II) Chemistry

Chemistry Gen

PART – II   [CGT 21a]

Unit II. Basic physical chemistry II

           

1.     How the rate should be expressed for the hypothetical reaction A + 3B → 2C.What are the units of "reaction rate".

     

2.     The reaction A + 2B → products has the rate law, rate = k[A][B]3. If the concentration of B is doubled while that of A is unchanged, by what factor will the rate of reaction increase?

     

3.    The reaction A + 2B → products was found to follow the rate law, rate = k[A]2[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the temperature remains constant.

    

4.      Write units for a first-order rate constant.

       

5.      It takes 10.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25°C. How long will it take for the reaction to be 90% complete?

       

6.      A certain first order reaction A → B is 25% complete in 42 minutes at 25°C.

What is the half-life of the reaction?

       

7.      At 700 K, the rate constant for the following reaction is 6.2 × 10-4 min-1. How many minutes are required for 20% of a sample of cyclopropane isomerize to propene?

       

8.      A first-order reaction has a rate constant of 7.5 × 10-3 /s. What is the time required for the reaction to be 60% complete.

     

9.      For the chemical reaction A → C, a plot of 1/[A]t versus time was found to give a straight line with a positive slope. What is the order of reaction?

10.  For what order reaction does the half-life get longer as the initial concentration increases?

11.  At 25°C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1kJ/mol?

12.  If the Ea for the forward reaction is 25 kJ/mol and the enthalpy of reaction is -95 kJ/mol, what is Ea for the reverse reaction?

13.  According to the collision theory, all collisions do not lead to reaction. Give reason why not all collisions between reactant molecules lead to reaction?

14.  The rate constant for the first-order decomposition of C4H8 at 500°C is 9.2 × 10-3 s-1. How long will it take for 10.0% of a 0.100 M sample of C4H8 to decompose at 500°C?

15.  The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the net reaction H3AsO4 + 3I- + 2 H3O+ → H3AsO3 + I3-+ H2O.

The experimental rate law for this reaction is Rate = k[H3AsO4][I-][H3O+].

What is the order of the reaction with respect to I- ?

16.  The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times) will the rate constant increase when the temperature is raised from 310 K to 325 K?

Fehling’s Reagent:

It comprises of two solutions.

Fehling solution A & Fehling solution B.

Fehling solution A is aqueous copper sulphate.  

Fehling solution B is alkaline sodium potassium tartarate. (Rochelle salt).

Caoutchoucine

Caoutchoucine is distillate of India rubber.

Now a days it is termed as Isoprene. The structural formula of Isoprene is

(Calcutta University) BSc (Chemistry) II Practice Questions

CGT 22a

Unit I. Basic physical chemistry III

1.       What are the limitations of thermodynamics?

2.       What do you mean by state function and path function?

3.       State Zeroth law of thermodynamics?

4.       Explain why C_p is always greater than C_v ?

5.       Compare the magnitude of work of expansion of an ideal gas and a real gas?

6.       What is the relation between heat of reaction at constant pressure(q_p) volume (q_v).

7.       Derive the expression, w = C_v (T₂-T₁), for the work done for the adiabatic reversible expansion of an ideal gas.

8.       What is the thermodynamic basis of Hess’s law?

9.       Bomb calorimeter involves combustion in a closed vessel i.e. ∆V =0. Then ∆H = ∆U + P∆V should give ∆H + ∆U. Is it true? Why or why not?

10.   What is meant by efficiency of engine? Explain the terms, source and sink.

11.   Prove that in a reversible process not entropy change for the system and surroundings is zero.

12.   Write the expression for the efficiency of Carnot cycle in terms of work done, heat absorbed and temperatures of the source and sink.

13.    At absolute zero, the entropy of all pure elements and compounds is zero. Explain?

14.   Write the mathematical expression for the entropy change taking place in the working substance under each of the following circumstances.

(a)    Free expansion of 1 mole of an ideal gas from V₁ to V₂.

(b)   Reversible, isothermal phase transition.

(c)    Reversible adiabatic expansion of 1 mole of an ideal gas from V₁ to V₂.

(d)   Reversible isothermal expansion of 1 mole of an ideal gas from V₁ to V₂.

15.   Write Gibbs-Helmholtz equation.

(Calcutta University) BSc (Chemistry) II Practice questions

Chemistry Gen: Course Description Year 2 [PART II]

Practice questions

 Unit I. Basic physical chemistry I

1. When you place ice cubes on the table on a hot summer day, they melt and the liquid water then evaporates. What happens to dry ice (solid carbon dioxide) if it is left on the table? (2)
2. Explain using kinetic molecular theory, why pressure exerted by gases is in all directions? (2)
3. A sample of nitrogen gas has a volume of 10L at 101.3kPa and 20⁰C. To preserve biological tissue, the nitrogen gas is cooled to -190⁰C, almost the temperature of liquid nitrogen, at a pressure of 101.3kPa. What volume will the nitrogen occupy at this temperature? (2)
4. A stone is dropped from the top of a cliff and is found to travel 44.1m diving the last second before it reaches the ground. What is the height of the cliff? g = 9.8m/s² (2)
5. If an 8g sample of a gas occupies 12.3L at 400 torr, what volume will the gas occupy at the same temperature and 600 torr? (2)
6. If a 9.3g sample of a gas occupies 12.3 L at 750 torr and 450K, what volume will the gas occupy at the same pressure and 25⁰C? (2)
7. Evaluate R if 1 mole of an ideal gas occupies 22.4L at 1 atm and 0⁰C. (2)
8. A 40L sample of N2 is collected over water at 220C and an atmospheric pressure of 727 torr. Calculate the volume that the dry N2 will occupy at 1 atm and 0⁰C. The vapor pressure of water is 20 torr at 22⁰C. (2)
9. A 1 mole sample of argon exerts a pressure of 64.2 atm in a 0.25 L container at 223K. Calculate the pressure, P_ideal assuming ideal gas behavior. (2)
10. Why is the molar heat capacity of molecular hydrogen not [7/2 R] at all temperatures? (2)
11. Why classical mechanics fails and quantum mechanics succeeds in correctly predicting the observed heat capacities of gases. (2)
12. Why is ice less dense than liquid water while H₂S (s) is more dense than H₂S (l)? (3)
13. Why does water have a high specific heat? (2)
14. A vessel is filled with gas at some equilibrium pressure and temperature. Can all gas molecules in the vessel have the same speed? (2)
15. An ideal gas is contained in a vessel at 300K. If the temperature is increased to 900K, by what factor does each one of the following change? (a) the average kinetic energy of the molecules. (b) the rms molecular speed. (c) the average momentum change of one molecule in a collision with a wall. (d) the rate of collisions of molecules with walls. (e) the pressure of the gas. (5)

Origin of Ortho-, Meta- and Para- Nomenclature

The prefix ortho- comes from the Greek ortho-, meaning “true or correct,” 
The prefix meta- comes from the Greek meta-, meaning “following or after.” 
The prefix para- comes from the Greek para-, meaning “akin to or similar.”

http://www.artsci.uc.edu/chemistry/faculty_staff/jensen/W.%20B.%20Jensen/Reprints/126.%20Othro,%20Meta,%20Para.pdf

What happens to dry ice (solid carbon dioxide) if it is left on the table?

Question: When you place ice cubes on the table on a hot summer day, they melt and the liquid water then evaporates. What happens to dry ice (solid carbon dioxide) if it is left on the table?

Answer: The vapour pressure of dry ice exceeds atmospheric pressure at room temperature. Therefore, dry ice sublimes. The carbon dioxide changes directly from a solid state to a gaseous state.

Ethynylmagnesium bromide

Ethynylmagnesium bromide or bis(bromomagnesium)-acetylene BrMgCCMgBr is very important Grignard reagent. It is useful in preparing disubstituted acetylene derivatives. Acetylenic Grignard reagent do not react with metal halides. They are very useful reagents for reaction with highly reactive compounds.

From Handbook of Grignard Reagents

Atomic Symbols. ( VIII Class)

Write Atomic Symbols of the following elements:

1.   Iron
2.   Lead
3.   Mercury
4.   Gold
5.   Cobalt
6.   Fluorine
7.   Radon
8.   Germanium
9.   Silicon
10. Copper

Shapes of Solids (basic)

New year Bengali Style (Netaji Subhash chandra Bose and Rabindranath Tagore along with our respectable Icons)

Lewis Symbol

Conversions

This is Fact

Don't read the word, but try to say the color of the word in which it is printed.

Albert Einstein

Two-Headed Shark Found by Fisherman

Two-Headed Shark Found by Fisherman

Recognizing a stroke

I URGE ALL MY FRIENDS TO READ & SHARE THIS; YOU COULD SAVE A LOVED ONES LIFE BY KNOWING THIS SIMPLE INFORMATION!!!Stroke has a new indicator! They say if you forward this to ten people, you stand a chance of saving one life. Will you send this along? Blood Clots/Stroke - They Now Have a Fourth Indicator, the Tongue:During a BBQ, a woman stumbled and took a little fall - she assured everyone that she was fine (they offered to call paramedics) ...she said she had just tripped over a brick because of her new shoes.

They got her cleaned up and got her a new plate of food. While she appeared a bit shaken up, Jane went about enjoying herself the rest of the evening.

Jane's husband called later telling everyone that his wife had been taken to the hospital - (at 6:00 PM Jane passed away.) She had suffered a stroke at the BBQ. Had they known how to identify the signs of a stroke, perhaps Jane would be with us today. Some don't die. They end up in a helpless, hopeless condition instead.

It only takes a minute to read this.

A neurologist says that if he can get to a stroke victim within 3 hours he can totally reverse the effects of a stroke...totally. He said the trick was getting a stroke recognized, diagnosed, and then getting the patient medically cared for within 3 hours, which is tough.

RECOGNIZING A STROKE

Thank God for the sense to remember the '3' steps, STR. Read and

Learn!

Sometimes symptoms of a stroke are difficult to identify. Unfortunately, the lack of awareness spells disaster. The stroke victim may suffer severe brain damage when people nearby fail to recognize the symptoms of a stroke.

Now doctors say a bystander can recognize a stroke by asking three simple questions:

S *Ask the individual to SMILE.

T *Ask the person to TALK and SPEAK A

SIMPLE SENTENCE (Coherently)
(i.e. Chicken Soup)

R *Ask him or her to RAISE BOTH ARMS.

If he or she has trouble with ANY ONE of these tasks, call emergency number immediately and describe the symptoms to the dispatcher.

New Sign of a Stroke -------- Stick out Your Tongue

NOTE: Another 'sign' of a stroke is this: Ask the person to 'stick' out his tongue. If the tongue is

'crooked', if it goes to one side or the other that is also an indication of a stroke.

A cardiologist says if everyone who gets this e-mail sends it to 10 people; you can bet that at least one life will be saved.

I have done my part. Will you?
They got her cleaned up and got her a new plate of food. While she appeared a bit shaken up, Jane went about enjoying herself the rest of the evening.
Jane's husband called later telling everyone that his wife had been taken to the hospital - (at 6:00 PM Jane passed away.) She had suffered a stroke at the BBQ. Had they known how to identify the signs of a stroke, perhaps Jane would be with us today. Some don't die. They end up in a helpless, hopeless condition instead.
It only takes a minute to read this.
A neurologist says that if he can get to a stroke victim within 3 hours he can totally reverse the effects of a stroke...totally. He said the trick was getting a stroke recognized, diagnosed, and then getting the patient medically cared for within 3 hours, which is tough.
RECOGNIZING A STROKE
Thank God for the sense to remember the '3' steps, STR. Read and
Learn!
Sometimes symptoms of a stroke are difficult to identify. Unfortunately, the lack of awareness spells disaster. The stroke victim may suffer severe brain damage when people nearby fail to recognize the symptoms of a stroke.
Now doctors say a bystander can recognize a stroke by asking three simple questions:
S *Ask the individual to SMILE.
T *Ask the person to TALK and SPEAK A
SIMPLE SENTENCE (Coherently)(i.e. Chicken Soup)
R *Ask him or her to RAISE BOTH ARMS.
If he or she has trouble with ANY ONE of these tasks, call emergency number immediately and describe the symptoms to the dispatcher.
New Sign of a Stroke -------- Stick out Your Tongue
NOTE: Another 'sign' of a stroke is this: Ask the person to 'stick' out his tongue. If the tongue is
'crooked', if it goes to one side or the other that is also an indication of a stroke.
A cardiologist says if everyone who gets this e-mail sends it to 10 people; you can bet that at least one life will be saved.
I have done my part. Will you?
Courtesy https://www.facebook.com/ProudToBeAnIndian.in

creativity

Super fluid Helium

Super fluid Helium has unique behavior different from other liquids  

-         It can dribble through molecule thin cracks.

     -         Climb up and over the side of a dish.

     

     -          Remains motionless when its container spun.

    

      -         Flows without friction.

                                                                                     

Human Eye and Colourful World (CBSE) Class X (Physics)

HUMAN EYE AND COLOURFUL WORLD

(Each question is of 2 marks)

Class X (CBSE) Physics

1.      Why when the sun is overheated at noon, it appears white but when the same sun is near the horizon at sunset, it appears red?

2.      Why stars twinkle at night?

3.      Why ocean is blue in colour?

4.      When we enter the dim light room from bright sunlight outside, why does it take time to see the objects clearly?

5.      How rainbow is formed?

6.      A boy uses spectacles of focal length 50cm. name the defect of vision he is suffering from.

7.      A man can read the number of distant bus clearly but he finds difficulty in reading book. What disease he is having?

8.      Astronauts observe the sky as dark instead of blue why?

9.      Why planets do not twinkle?

10.  Why is a normal eye not able to see clearly the objects placed closer than 25cm.

Heredity and Evolution (Class X) CBSE test paper

Heredity and Evolution

(All questions are of 1 mark)

1.      What are fossils?

2.      What is monohybrid cross?]

3.      Give two examples of analogous organs.

4.      What are vestigial organs?

5.      What are dominant genes?

6.      Define the term evolution.

7.      What is scientific name of Human Beings?

8.      What are allosomes?

9.      Write the scientific term used for ‘Science of Heredity and variation’.

10.  Radish and carrot are homologous or analogous structures?

11.  Write the name of different types of possible blood groups?

12.  Define F1 generation.

13.  What will be the sex of the embryo if an egg is fertilized by the sperm having 22+y composition?

14.  What is dihybrid cross?

15.  Define the term progeny.

Test paper on Periodic classification of the elements (X) CBSE

Periodic classification of the elements.

(CBSE) Class X Test

1. Write electronic configuration of C and Na.  (1)

2. The atom of an electronic configuration 2 8 8 2 belongs to which period? (1)

3. Which is more reactive F or Cl?  (1)

4. Which is bigger in size Cl/Cl^- ? (1)

5. Define the law of Octaves? (2)

6. Why elements of a same group show same valency? (2)

7. Discuss the position of H atom in a periodic table. (2)

8. Differentiate metals and non metals? (2)

9. Define modern periodic law. (2)

10.What are metalloids? Explain with example. (2)

Lewis structures of chemical compound

Draw Lewis Structure of following

1. NH₃

2. CO

3. CO₂

4. CH₄

5. HNO₃

6. HCl

Chemistry (Class X)(CBSE) Second term test paper on periodic classification of elements)

Class X (CBSE)

Second Term

 

PERIODIC CLASSIFICATION OF ELEMENTS:

 

Note: Question 1-3 are 1 mark each, Questions 4-10 are 2 marks each.

 

1.      What is general trend in atomic size as you move from left to right in a period?

2.      Why all the atoms of a period have different chemical properties?

3.      How many electrons are present in valence shell of Cl?

4.      What are the limitations of Dobernier’s classification?

5.      What are noble gases? Explain their characteristics?

6.      Write the electronic configuration of Na, O, F and C.

7.      Explain out of ‘Na’ and ‘K’ who is more electropositive in nature?

8.      Why atomic number of an element is more important than its mass number?

9.      Compare Na and K with respect to their valence, formula of their oxide and formula of their chloride.

10.  Atomic number of an element X is 17. Predict its valence and tell whether it is metal or non metal?

CBSE X (Chemistry) Second term (Test paper)

Class X

Second term

Unit: Chemical Substances –Nature and Behaviour

CARBON COMPOUNDS

(Question 1-10 are 1 Mark, Question 11-14 are 2 Marks and Question 15-18 are 3 Marks)

1.       Name the following functional group.  (–OH, -COOH)

2.       Give electron dot structure of CH₃Cl.

3.       Write formula of methanol.

4.       Draw structure of Chlorobutane.

5.       What are oxidizing agents?

6.       Name the functional group present in the compound               CH₃CH₂NH₂.

7.       What is the odour of the acetic acid like?

8.       Name the CH₃C=CH.

9.       How many C-H bonds are present in ethane C₂H₆.

10.   What is the need to denature alcohol?

11.   Give one example of substitution reaction.

12.   Draw structural formula of all isomers of hexane.

13.   Write chemical equation showing decarboxylation reaction of ethanoic acid.

14.   What are enzymes? Name the enzyme which ferments sugar cane to ethanol?

15.   What are synthetic detergents? Give example and how it is better than soap?

16.   What is homologous series? Explain with example. By how many carbon atoms and hydrogen atoms do any two adjacent homologues differ?

17.   What are esters? Write chemical equation showing formation of ester?

18.   Write  the reaction and name the products formed.

a)      Acetic acid and sodium hydroxide are heated together.

b)      Ethanol is burnt in oxygen in the presence of alkaline KMnO₄

   

Compound interest

Compound Interest

 (i)                  Find the amount and the 

             compound interest on 8000 

              at 5% p.a for 2 years.

Principal = Rs 8000/-

Rate of Interest = 5% p.a

Interest for the first year 

= 8000 x 5% x 1/100 = Rs 400

                                  

                 Amount for the first year or 

                  principal for the second year

                              = (8000 + 400) Rs = 8400 Rs

   

Interest for the second year 

= 8400 x 5% x 1/100 = Rs 420

                               Amount for the second year

                              =  (8400 + 420) Rs = 8820 Rs

                              Total Compound Interest

                              = 8820 – 8000 Rs = Rs 820  

chemistry test paper (XII) Amines, biomolecules, polymers, chemistry in every day life

TEST PAPER-CHEMISTRY

CLASS-XII

1.    Draw resonance structures of Aniline?

2.    Write Hoffman elemination reaction?

3.    Draw D-Glucose?

4.    What is muta – rotation?

5.    Explain tertiary structure of Proteins?

6.    Write defination of Enzyme?

7.    Write difference between Fibrous proteins and Globulor Proteins?

8.    Write  structure of Nylon-6?

9.    Define polymerisation?

10.  What is denaturation of portein?

11.  What is Condensation Polymerisation?

12.  What are antacids?

13.  What is Hard Water?

14.  Draw Structure of Zwitter-ion from of alpha amino acetic acid?

15.  What is translation?

If you want to solve chemistry final papers chemistry XII (CBSE) paper. Leave message or comment for sample papers.