Recent

Search This Blog

Theme images by Storman. Powered by Blogger.

Followers

Recent in Sports

Home Ads

Comments

Ads

Random Posts

Zoology Viva Questions and Answers

- No comments

Zoology Practical Viva Questions and Answers

Investigatory Project on Setting up and Maintenance of an Aquarium


1. What is an aquarium?


Aquarium is an open rectangular glass tank providing a condition similar to pond for the growth of fishes and water plants.


2. Name two ornamental fishes?


Gold Fish (Carassius auratus) and Guppy (Poecilia reticulata)


3. Name two water plants used in an aquarium?


Hydrilla and Valisnaria


Investigatory Project on Some insect pests and their control


4. What are pests?


Pests are organisms which destroy and damage crops and food grains during various stages of cultivation and storage.


5. Name any two paddy pests.


Leptocoriza acuta and Tryporyza incertulas.


6. Name a pest that attacks coconut palm.


Oryctes rhinoceros


Investigatory Project on Prepare an account of wild animals after visiting a Zoo or National Park


7. What is wildlife? Give example.


The uncultivated species of plants and animals living in their natural habitat is known as wild-life.


8. Give the scientific names of lion and elephant.


Panthera leo and Elephas maximus


9. What is Project Tiger?


It is a scheme to protect tigers from extinction. It was launched by the Govt. of India in 1973.


Investigatory Project on Control of Mosquitoes


10. Name the different species of mosquitoes found in your locality.


Anopheles, Culex and Aedes mosquitoes


11. Name two larvivorous fishes.


Gambusia and Aplocheilus


12. Name the diseases spread by Culex, Anopheles and Aedes


Culex – Elephantiasis

Anopheles – Malaria

Aedes – Dengue fever


Investigatory Project on Preparation of a report with illustration and photos from newspapers and magazines dealing with pollution


13. What is pollution?


Undesirable change in the physical, chemical and biological characteristic of air, water and land that may harmfully affect the living beings including man is called pollution.


14. What are pollutants?


The agents that cause pollution are known as pollutants.


15. Name any three air pollutants?


Carbon monoxide, Sulphur dioxide and Hydrocarbons


16. Distinguish between degradable and non degradable pollutants?


Pollutants which are degraded by microbial action and radiation are called degradable pollutants.

Eg: Domestic Sewage


The pollutants which are not degraded are known as non-degradable pollutants.

Eg: DDT


Investigatory Project on DNA Model


17. What is DNA?


DNA or Deoxyribo Nucleic Acid is the genetic material in all organisms except certain viruses.


18. Who proposed the double helix model of DNA?


Watson and Crick (1953)


19. Name the nitrogen bases found in DNA.


Adenine, guanine, cytosine and thymine


20. Expand DNA


Deoxyribo Nucleic Acid


21. Which is the functional unit of DNA?


Gene


Investigatory Project on Survey of Human Phenotypic Characters


22. What is phenotype?


The visible characters of an organism are known as phenotypic characters.


23. What is genotype?


The genetic constitution of an organism is known as genotype.


24. What do you mean by hereditary characters?


The characters which transmit from parents to offspring are known as hereditary characters.


25. Name any two phenotypic characters that are heritable.


Fused ear lobes and rolling of tongue.


Investigatory Project on Preparation of Vermi Compost using household wastes, market wastes etc.


26. What is vermin compost?


It is the excretory product of earthworm rich in nutrients and minerals.


27. Name the elements found in vermin compost.


Nitrogen, potassium, and phosphorus


28. Mention the merits of vermin compost.


Vermi compost is safe, economic and ecofriendly.


Investigatory Project on Preparation of Rectal Ciliates in Amphibians


29. Name any two ciliates found in the rectum of frog.


Opalina and balantidium


30. What are ciliates?


Ciliates are unicellular animals. They possess cilia. They belong to the phylum protozoa.


Investigatory Project on Study on the Bird Fauna in the Locality


31. What is Ornithology?


Study of birds is known as ornithology


32. Who is called Bird Man of India?


Dr. Salim Ali


33. Name two birds found in your locality.


Crow and Bulbul

Vibrations of Air Column in Pipes

- No comments

Investigatory Project – I


Vibrations of Air Column in Pipes – I


Aim: To study the factors affecting the resonant length of closed pipes.


Apparatus: Resonance column apparatus, Tuning forks, Rubber hammer, Metre scale etc.


Theory: In closed pipes, an antinode is formed at the open end and a node at the closed end. The distance between a node and the nearest antinode is λ/4. If ‘l’ is the length of the closed pipe, then l = λ/4.


Therefore, λ = 4l


The resonance occurs when the frequency of the tuning fork equals the frequency of natural vibrations of the closed pipe. Let v is the velocity of sound through air and n is the frequency of the tuning fork, then at resonance,


n = v/ λ = v/4l  or

l = v/4n


The velocity of sound is a constant at constant temperature.


Therefore, l 1/n or resonance length varies inversely with the frequency of the tuning fork.


Procedure:


Set the resonance column apparatus for experiment. Length of the air column is kept very small. A tuning fork of known frequency n, is excited and held horizontally near the mouth of the inner tube. The length of air column is measured. This is repeated again and the average length of the air column is determined. The experiment is repeated for tuning forks of different frequencies and the results are tabulated.


Observations and Calculations


Room temperature in the beginning = ____°C

Room temperature at the end = ____°C


Frequency of the tuning fork (Hz)

First resonating length

Mean resonance length (cm)

1 (cm)

2 (cm)

 

 

 

 

 

 


Report:


At constant temperature the resonance length of closed pipes decreases with the increase in frequency of the driving source.


Investigatory Project – II


Vibrations of Air Column in Pipes – 2


Aim: To study the factors affecting the resonant length of closed pipe.


Apparatus: Resonance column apparatus, Tuning fork, Rubber hammer, Metre scale etc.


Theory: The wavelength (λ) corresponding to first resonating (l) is given by,

λ/4 = l +e, where end correction e = 0.3D, D is the inner diameter of the pipe.

The velocity of sound at room temperature (t) is v(t) = 4n(l+e) where n is the frequency of the tuning fork. At constant temperature, velocity of sound is a constant.

l 1/n

For constant n, λ is constant

Therefore, resonating length l (first resonating length observed) varies with diameter of the pipe.


Procedure:


Set the resonance column apparatus for experiment. Length of the air column is kept very small. A tuning fork of known frequency n, is excited and held horizontally over the mouth of the inner tube. The length of air column in the inner tube is slowly increased by raising the tube till a booming sound is heard. The length of the air column is measured. This is repeated again and the average length of the air column is determined. The experiment is repeated for pipes of different inner diameters.


Observations and Calculations


Frequency of the tuning fork, n = ___ Hz

Room temperature, t = ___°C

To study the vibration of resonating length with inner diameter of the pipe


Trial No:

Inner diameter of tube D (cm)

First resonating length, l (cm)

1

2

3

4

5

 

 

 

Report:


The resonating length of closed pipe with its inner diameter at constant temperature is studied.

Galileo Experiment on Motion

- No comments

Galileo Experiment on Motion Investigatory Project


Aim


To study the first law of motion by the double inclined track.


Apparatus


Double inclined track, Metal ball, Glass plate of same thickness, Wooden block etc. The double inclined track apparatus consists of a pair of inclined tracks, each of them can be independently set at a small angle of inclination.


Theory


A body will continue its state of rest or uniform motion along a straight line unless an external resultant force acts on it.


Procedure

Set up the double inclined track on the table. Clean the metal ball and the track using cotton or tissue paper. Insert the wooden block under the right arm at such a position that the track is inclined at a suitable angle (nearly 45°) with the horizontal. Then left arm is arranged at a suitable angle of inclination. This is done by placing a number of glass plates below it (say 14). A point 'B' is marked on the right arm which is at a distance 10 cm from the lower edge. The metal ball is released from 'B' and the distance 'd' to which it ascends in the left arm is noted. The experiment is repeated for different angle of inclinations in the left arm. This can be done by changing the number of glass plates below it. Since the glass plates are of same thickness, the slope of the left arm will be proportional to the number of glass plates (n).


A graph is plotted with number of glass plates (n) along the X-axis and the reciprocal of the distance 'd' along the Y-axis. The graph would be a straight line. On extrapolating the graph to slope zero (ie, n=0), it is found that 1/D is nearly zero or d = ∞, which implies that the body will continue its motion along a straight line. This verifies the validity of the first law of motion.


Observations and Calculations


Trial

No: of glass plates below the left arm (n)

Distance of ascend along the left arm (d)

1/d

1

2

Mean (d)

-

-

cm

cm

cm

cm-1

1

2

3

4

5

6

14

12

10

8

6

4

 

 

 

 


Report 


This experiment verifies that in the absence of an external force, a body in uniform motion would continue its motion indefinitely along a straight line.

Effect of particle size on rate of chemical reaction

- No comments

Investigatory project on study of the effect of particle size on rate of chemical reaction

Principle


In reactions involving solids, the reaction usually takes place on the surface and the rate of the reaction depends on the surface area of the solid particles. The greater the surface area, the higher will be the rate of the reaction. The surface area of a given mass of solid depends on the size of the particle. For a given amount of a solid, the surface area increases with the decrease in size of the particle. So smaller the particles, greater will be the rate of reaction.


Objective


The objective of this project is to study the influence of the size of particles on the rate of a reaction by considering the reaction between marble and hydrochloric acid.

CaCO3 + 2HCl ---> CaCl2 + H2O + CO2


Requirements


250 mL beakers, Marble pieces, HCI acid, Stop watch


Procedure


Take one single piece of marble weighing 2g. Similarly take 2g samples of coarsely powdered marble and finely powdered marble. Place the three samples in three different beakers. Add the same quantity of 2M HCl (not less than 50 mL) to each of them. There should be enough acid to completely immerse the samples. As soon as HCI is added, start a stop watch. The contents may be shaken at regular intervals. Note the time taken in each case to complete the reaction. The reaction will be slowest when a single piece of marble is reacted. It is fastest when finely powdered sample is reacted.


No

Nature of marble (2g)

Volume of 2M HCl in mL

Time taken to complete the reaction

1

2

3

Fine powder

Coarse powder

Single piece

50

50

50

-

-

-

 

It is observed from the experiment that minimum time is taken for the completion of reaction when marble is in the powdered form.


Conclusion


The rate of reaction of a solid substance is proportional to the surface area of the sample.


VIVA QUESTIONS WITH ANSWERS


1. How does the rate of a reaction vary with increase in surface area?


Ans: Rate of a reaction increases with increase in surface area


2. Why are powdered substances more reactive than substances in lump states?


Ans: Surface area of powdered substances are more than that of a substance in the lump state.


3. What is the action of dil.HCI on marble?


Ans: Marble reacts with HCl to liberate CO2.


4. Write the reaction between marble and HCl


Ans: CaCO3 + 2HCl ---> CaCl2 + H2O + CO2

Rate of Flow of Liquid Investigatory Project

- No comments

Investigatory Project on comparative study of the rate of flow of liquids

Introduction: Liquids have flow properties. Some liquids flow faster than some others. This difference in the rate of flow of liquid is due to a property called viscosity. Viscosity of a liquid is its resistance to flow. A liquid with high viscosity will flow comparatively slowly. Viscosities of different liquids can be compared in terms of coefficient of viscosity. It is described as the force in dynes per square centimeter necessary to maintain a difference in velocity of 1 cm per second between two parallel layers of liquid held at a distance of 1cm from one another. It is denoted by η and expressed in millipoise. The rates of flow of liquids are compared by taking them in a viscometer and allowing them to flow through a fixed distance and measuring the time taken in each case.


Objective: The objective of this project is to compare the rates of flow of different liquids such as water, coconut oil, benzene, glycerine etc.


Requirements: Viscometer, Stop watch, Liquids like water, coconut oil, benzene, glycerine etc.


Procedure: Take one of the liquids, say water (about 25mL) in the bulb 'A' of a clean and dry viscometer. Suck up the liquid into bulb 'B' so that it is slightly above the mark 'C' of the viscometer. Allow the liquid to fall through the capillary. Note the time taken for the meniscus of the liquid to fall from the mark 'C' to 'D' by using a stop watch. Repeat the experiment three times with the same liquid. Wash and dry the viscometer. Repeat the above experiment with the other liquids and tabulate the results.


Liquid

Time taken

Density d

η liquid/ η water

t1

t2

t3

Mean t

Water

-

-

-

-

 

 

Coconut oil

-

-

-

-

 

 

Benzene

-

-

-

-

 

 

Glycerine

-

-

-

-

 

 

 

η liquid/η water can be calculated using the relationship.

η liquid/η water = t liquid/t water x d liquid/d water

Where t liquid and t water are the time taken for the flow of liquid and water respectively and d liquid and d water are the densities of the liquid and water respectively.


Conclusion:


Liquids which flow readily have low viscosity, while those which flow slowly have high viscosity.


Viva Questions with Answers


1. What is viscosity of a liquid?


Ans: Resistance to the flow of a liquid is known as viscosity.


2. Which has higher viscocity, water or coconut oil?


Ans: Coconut oil


3. Which instrument is used to measure viscosity?


Ans: Viscometer


4. Why is coconut oil more viscous than water?


Ans: Different liquid layers in coconut oil are attracted by hydrogen bonding.

Investigatory Project on Diffusion of Solids in Liquids

- No comments

Investigatory Project and Viva Questions on Diffusion of Solids in Liquids (Class 12)

The process of intermixing of substances when they are brought into contact with each other is called diffusion. Diffusion occurs rapidly in the case of gases. In the case of liquids it is less rapid and solids do not show this property when they are brought into contact. However, diffusion of solids occurs slowly in liquids in which they are soluble. The speed of diffusion depends on (a) temperature (b) size of the particles and (c) the mass of the particles.


Aim


The aim of this investigatory project is to study the effect of temperature on rate of diffusion of a solid in a liquid by taking crystals of copper sulphate.


Materials and Requirements


250 mL beakers, Crystalline copper sulphate, Distilled water, Ice, Stop watch etc.


Procedure


Take 5g each of CuSO4. 5H20 in three 250 mL beakers. Pour 100 mL of distilled water into one of the beakers, 100 mL ice water into the second beaker and 100mL hot water into the third beaker. Cover all the three beakers with watch glasses. Note the temperature of each. Observe the development of blue colour (due to diffusion). Record the time taken for the complete dissolution and diffusion of CuSO4 in all the three cases.


No.

Temperature

Time taken in minute

1

2

3

Cold water

Distilled water

Hot water

-

-

-

 

It is found that the diffusion occurs most readily in the hot solution.


Conclusion


The rate of diffusion of a solid in a liquid is directly proportional to temperature.


VIVA QUESTIONS ON DIFFUSION OF SOLIDS IN LIQUIDS


1. What is diffusion?


Ans: Intermixing of different substances when they are brought into contact with each other is called diffusion


2. Which type of substance has maximum diffusion?


Ans: Gases have maximum diffusion.


3. What are the factors which influence diffusion?


Ans: The rate of diffusion depends on the temperature, size of particles and the mass of particles.


4. Explain effect of temperature on rate of diffusion of a solid in a liquid?


Ans: Here when the temperature increases, the rate of diffusion also increases.


5. What colour is developed when copper sulphate is dissolved in water?


Ans: Blue


6. Equal masses of crystalline copper sulphate are added to equal volumes of water taken in two beakers which are kept at two different temperatures. Which water gets the blue colour earlier?


Ans: Water which has higher temperature

Investigatory Project on Caffeine in Tea

- No comments

Determination of caffeine in tea samples Investigatory Project (Class 12)

Tea leaves contain up to 4% caffeine. They also contain tannic acid and colouring matter. The relative amounts of these substances differ in different samples of tea.


Theory:


Caffeine is more soluble in chloroform than in water. So it can be extracted from aqueous solutions by chloroform. But the tannic acid present in tea leaves must be removed before the extraction of caffeine. Tannic acid is removed as calcium tannate.


Aim:


The aim of this experiment is to determine the percentage of caffeine present in different samples of tea leaves and to find out the best tea leaves.


Requirements:


1. Different brands of tea leaves

2. Beakers

3. CaCO3

4. Chloroform


Procedure:


Take 10g each of the given sample of tea leaves and boil with about 100mL of distilled water in a beaker for about 10 minutes. Cool and filter. Add 2g CaCO3 and boil. Remove the precipitated calcium tannate by filtration. Extract the filtrate at least 3 times with chloroform. Distil off the chloroform. The residue is caffeine. Weigh it. In the ssame way, determine the amounts of caffeine in other samples of tea and tabulate.


No:

Brand name of the tea

Mass of tea (x)

Mass of caffeine (y)

% of Caffeine (y x 100)/x

1

2

3

 

 

 

 

 

Conclusion:


The tea containing the highest percentage of caffeine is ……. Hence it is the beast tea among the samples analysed.


VIVA QUESTIONS WITH ANSWERS


1. What is the percentage of caffeine in tea leaves?


Ans: About 4%


2. How will you remove tannic acid from tea leaves?


Ans: By boiling with calcium carbonate


3. What is the product formed when tannic acid is boiled with CaCO3?


Ans: Calcium tannate


4. How will you determine the quality of a sample of tea based on the caffeine content?


Ans: The sample with maximum caffeine content is the best quality tea.


Effect of Catalyst on Rate of Reaction (Class 12)

- No comments

 

Investigatory Project on Effect of Catalyst on Rate of Reaction (Class 12)

Principle: A catalyst is a substance which alters the rate of a reaction without it is being consumed in the reaction. A catalyst may speed up a reaction and then it will be called a positive catalyst. It may slow down a reaction and then it will be called a negative catalyst. Their functions can be illustrated by studying the decomposition of hydrogen peroxide in the presence of various substances.


2H2O2 --> 2H2O + O2


Aim: The aim of the investigatory project is to study the influence of catalysts on the rate of reaction.


Materials Required: Hydrogen peroxide, MnO2, HCl, NaOH, Al powder, Test tubes


Procedure:


Pour 10mL portions of 20 volume hydrogen peroxide into four test-tubes. To each of the test tube add the following substances and note the rates at which bubbles evolve in each case.


1. 5 drops of 2M NaOH

2. 5 drops of 2M HCl

3. About 10 mg of MnO2

4. About 10 mg of Aluminium powder


Except in the case of adding HCl, in all other cases effervescence is seen. The briskness of the effervescence may be taken as a measure of the effectiveness of the catalyst in decomposing hydrogen peroxide. It becomes evident that while HCl acts as a negative catalyst, the other three act as positive catalysts.


Conclusion:


It is concluded from the experiment that the rate of reaction increases with a positive catalyst and decreases with a negative catalyst.


Viva Questions with Answers


1. What is a catalyst?


Ans: A substance which alters the rate of a reaction without itself undergoing any permanent chemical change is called a catalyst.


2. What is a positive catalyst?


Ans: A catalyst which increases the rate of a reaction is called a positive catalyst.


3. Give the example of a positive catalyst?


Ans: MnO2 in the dissociation of hydrogen peroxide to produce O2 and water.


4. What is a negative catalyst?


Ans: A catalyst which decreases the rate of a reaction is called a negative catalyst.


5. Give the example of a negative catalyst.


Ans: Hydrochloric acid in the dissociation of hydrogen peroxide.