chemistry session plan

7/31/2019 chemistry session plan

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Session 1Session Name:pH-Metry in Chemical

AnalysisAuthor Name: Z. D. Sande

Department: General EngineeringSubject/Course: Engineering Chemistry


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Session Objectives

At the end of this session, the learner will be able to:

List the advantages and disadvantages of instrumental methods ofchemical analysis.

Explain the importance of pH-metry in engineering applications.

Draw the Glass electrode for measurement of pH of any kind of solution.

Explain the construction and working of glass electrode.

Describe equation of pH using glass electrode.

Teaching Learning Material

White Board and Markers

Presentation

LCD Projector

Instrumental Methods of Chemical AnalysisPage 2 Ver : 1.01 Mr. Z. D. Sande Annasaheb Dange College of Engg. & Tech., Ashta


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Session Plan

Time

(in min) Content

Learning Aid and

Methodology

Faculty

Approach

Typical Student

Activity

Learning Outcomes

(Blooms +Gardeners)

10

Introduction toinstrumental methodsof chemical analysis,its advantages anddisadvantages

Questions andAnswers,

ExplainsFacilitates

ListensParticipates

Remembering

IntrapersonalVerbalLinguistic

10Importance of pH-metry in engineeringapplications

Brainstorming ExplainsFacilitates

ListensParticipates

Understanding

IntrapersonalLinguistic

10

Glass electrode, itsprinciple andconstruction withdiagram

PPT/ Charts Explains,Questions,Facilitates

Listens,Answers,Participates

Understand

Visual, Linguistic

05

Working of glasselectrode

Group Task ExplainsFacilitates

ListensParticipates

Apply

Visual, Linguistic

10Derivation ofequation of pH usingglass electrode

Board Activity Questions,Explains

Answers,Listens

UnderstandingVisualLogical

15 Conclusion

CrosswordPuzzle(using notes-stickers)

ExplainsFacilitates

ListensParticipatesAnswers

AnalyzingInterpersonalVerbal LinguisticKinesthetic

Please maintain the flow of the session by explaining the contentin such a way that one topic should be followed by the other topic.Give proper explanation of why the current topic is explained afterthe previous topic throughout the session.

Session Inputs



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Introduction to Instrumental Methods Of ChemicalAnalysis

Learners would have some basic knowledge about chemical analysis and itstypes. Therefore, we can conduct a question-answer activity to bring outthe advantages and disadvantages of instrumental methods.

Suggested Activity: Questioning

We can ask the following simple questions to the learners.1. What do you mean by chemical analysis?2. What do you mean by instrumental methods?3. Which is the best method of chemical analysis?4. Why instrumental methods are more advantageous than non-instrumental methods?5. Tell advantageous and disadvantages of instrumental methods?

Learners may give various answers. We can write these on the board, and discuss andanalyze the answers with the help of suitable examples.

Answers to these questions are like this:1. Chemical analysis deals with finding composition of a material.2. Chemical analysis in which instruments are used.

3. Instrumental methods4. Due to their accuracy, reliability, sensitivity, faster, use for complex

materials or mixtures, etc.5. Advantages: accuracy, sensitivity, reliability, faster, use for

complex materials or mixtures,not affected by oxidation-reductionpotential of solution, etc.

Disadvantages: Require skill/training, standardize/ calibrate,much costly, sensitivity/ accuracy depends on instrument.

Dear students, it is now clear that instrumental methods of

chemical analysis are more advantageous than non-instrumental or regular methods. Now, let us learn one of themost important and best methods of analyzing, which is pH-Metry.



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Importance of pH-metry in engineering applications:

Suggested Activity: BrainstormingAs the students have some basic knowledge about this topic, the classcan be divided into 4-5 groups, and each group needs to brainstorm theother group. One representative from each group can share their findings,and the answers can be written on the board in short. The incorrectanswers can be cancelled out, and the faculty can explain the correctanswers in detail.

PH metry is technic used to analyze materials by measuring pHwith the help of instrument pH meter.pH metry is useful in various engineering applications, such as:

i) Effluent treatmentii) Water testingiii) Corrosion monitoringiv) Quality Controlv) City water supplyvi) Scale formation in boilers

Glass electrode, its principle, construction and working

Please explain the principle, construction and working

Suggested Activity: Observe and Answer

Faculty can show the slides or charts containing such diagrams one byone. After each slide he can ask the names of different parts of the

diagram with their definitions, which they know.



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fig.(a)

fig.(b)



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fig.(c)

fig.(d)

Please explain all the block diagrams in detail for betterunderstanding.



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Derivation of equation of pH using glass electrode

Suggested Activity: QuestioningFaculty can ask questions to the students at each step on the basis of

their previous knowledge.

The formula for emf of a cell is:Ecell =ER EL

For given cell this formula is:

= ESCE - EGWhere, EG is emf of Glass Electrode. Now,using Nernst equationfor glass electrode,

= ESCE - {EG0- 2.303RT/nF log [H+]}

At 298 K eqn becomes as,= ESCE - {E

0- 0.0591 log [H+]}But, -log [H+]= pH, Hence,

= ESCE - {E0 + 0.0591 pH}

Ecell = ESCE - EG0 - 0.0591 pH

But ESCE = 0.2422 V & EG0 is known for glass

electrode.

Ecell = 0.2422 - EG0

- 0.0591 pH



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Conclusion

Faculty is supposed to write questions on different stickers with numbers 1 to

8 and stick on white board.Selected students at the end of session can be called one by one and asked totake any one sticker and find the answer and write on big card sheetcontaining cross-word puzzle.

Suggested Activity: Crossword Puzzle

Faculty can writequestions related to following answers on card sheets:

1. ELECTRODE2. CALOMEL

3. PLATINUM4. ETHANOL5. OPERATE6. EFFLUENTS7. BUFFER8. TWO


7

2 6 8

1

3

5


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SummaryIn this session, we learnt to:

List advantages and disadvantages of Instrumental Methods of ChemicalAnalysis

Compare Instrumental Methods with Non-instrumental methods

Draw glass electrode for measurement of pH of any kind of solution

Explain construction and working of glass electrode

Derive equation of pH using glass electrode



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Assignment

1. Draw the diagram of glass electrode used in pH-metry.

2. Explain construction and working of glass electrode.3. How will you derive equation of pH using glass electrode.



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References

Instrumental methods Chatwal and Anand

http://en.wikipedia.org/wiki/Glass_electrode

http://www.google.co.in/images

http://en.wikipedia.org/wiki/Glass_electrodehttp://www.google.co.in/imageshttp://en.wikipedia.org/wiki/Glass_electrodehttp://www.google.co.in/images

chemistry session plan

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