What are the most common and the most important questions viva

CBSE Class 12
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What are the most common and the most important questions viva that can be asked in chemistry practical exam class 12 cbse?

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Prepare the viva mainly from the practical manuals. Thoroughly understand all the concept based questions from your theory which are related to your practical examinations. For example: definitions, examples, abbreviations etc.

Salt Analysis/ Content based experiments:

  • You will have to perform each and every group analysis even if we are sure that the group is confirmed. This is because you will have to record your observation and conclusion for each of these tests in your answer sheet during your examination. As each main tests carries marks.
  • Preferably write all the confirmatory tests.
  • Do the confirmatory tests twice to be assured about the result.

For the Viva, the examiner can ask any questions related to the salt provided to you during the examination.

General Viva Questions for Volumetric Analysis:

  1. What is meant by volumetric analysis?
  2. Define – Titration, Volumetric Analysis, Titer, Titrant etc
  3. What is the use of indicator in the volumetric titrations?
  4. Give examples of the indicators used.
  5. Why removal of air bubbles is necessary before starting titration?
  6. What is the colour change/ end point of the titration carried out with the help of phenolphthalein indicator?
  7. What is the colour change/ end point of the titration carried out with the help of methyl orange indicator?
  8. What is the colour change/ end point of the titration carried out with the help of starch indicator?
  9. Tell 5 precautions of chemistry lab.
  10. What is the volume of the standard volumetric flask used for titration?
  11. What is the volume of the standard burette used for titration?
  12. What is the volume of the standard pipette used for titration?
  13. Meaning of lower and upper meniscus.
  14. 2/3 difference between-
  • Primary and Secondary Solution
  • End point and Equivalence point
  • Normality, Molarity and Strength.
  • Pipette & Graduated Pipette.
  1. Why only conical flask is used for titration?
  2. What precautions should be made during filling burette?
  3. Why always intermediate solution is filled in burette?
  4. Least count of burette and graduated pipette
  5. Examples of Standard, Primary, Secondary and Intermediate solutions.
  6. Why do we require intermediate solution?
  7. What do you mean by single and double titration?
  8. Why in colored solutions we observe upper meniscus and in colurless solutions lower meniscus?
  9. Name of all apparatuses used.
  10. Name the unknown, known, intermediate, indicator and others solutions (if used).
  11. Define concentration.