LAB MANUAL SK015 & SK025

SK015 & SK025 Lab Manual

(B) Oxidation with cold alkaline solution of KMnO4 (Baeyer’s Test)
1. Label dry, clean test tubes, G, H and I.
2. Place 1 mL each of cyclohexane, cyclohexene and toluene in test tubes G, H
and I, respectively.
3. Add a few drops of alkaline KMnO4 solution into each test tube and shake.
4. Record the observations.

EXERCISE
1. Write the mechanism for the reaction of cyclohexane with bro mine.
2. State the function of sunlight in Part (B).

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SK015 & SK025 Lab Manual

EXPERIMENT 5 REACTIONS OF HYDROXY COMPOUNDS

Course Learning Objective

Demonstrate the correct techniques in handling laboratory apparatus and chemicals when carrying
out experiments. (P3, PLO 2, MQF LOD 2)

Learning Outcomes

At the end of this lesson, students should be able to:
i. identify classes of alcohols.
ii. study the chemical properties of alcohols and phenol.

Student Learning Time (SLT)

Face-to-face Non face-to-face
2 hour 0

Introduction

Alcohols are organic compounds containing hydroxyl group, -OH, as the functional group.
Alcohols can be classified into:

H H R
R C OH R C OH R C OH

H R R [R = alkyl]

Primary alcohol (1o) Secondary alcohol (2o ) Tertiary alcohol (3o)

Lucas reagent, a mixture of concentrated hydrochloric acid and anhydrous zinc chloride,
can be used to differentiate the three classes of alcohols. Tertiary alcohols turn cloudy or
appear in two layers almost immediately. Secondary alcohols turn cloudy within 5 to 10
minutes whereas primary alcohols do not show any changes.

Alcohol can be oxidised to aldehyde, ketone or carboxylic acid. The product formed depends

on the class of alcohol used. Various oxidizing agent such as KMnO4, Na2Cr2O7and H2CrO4
can be used.

Phenol, an example of aromatic alcohol can be distinguished from aliphatic alcohol through
reactions with FeCl3 solution or bromine water.

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SK015 & SK025 Lab Manual

Apparatus Chemical reagents

Stopper Ethanol
Dropper 1-Butanol
Test tube
Stopwatch 2-Butanol
Water bath
Measuring cylinder (10 mL) Alcohol X
Lucas reagent
2-Methyl-2-propanol

Concentrated H2SO4
0.04 M Na2Cr2O7
Glacial acetic acid
Phenol
Bromine water

Procedure

(A) Lucas test

1. Place 1 mL of 2-methyl-2-propanol in a test tube.

2. Add 2 mL of Lucas reagent into the test tube.

3. Stopper and shake the test tube.

4. Record the observation and the time taken for the reaction to occur.

5. Repeat the above steps using 2-butanol, 1-butanol and alcohol X. If no change
occurs within 10 minutes, place the test tube in a water bath at 70 – 80C.

6. Deduce the class of alcohol X.

(B) Oxidation
1. Place 5 mL of 0.04 M Na2Cr2O7solution in a test tube.
2. Add 2 to 3 drops of concentrated H2SO4 to the solution in the fume cupboard.
3. Add 3 drops of 1-butanol to the mixture and heat it in a water bath at 70 – 80C.
4. Repeat the above steps using 2-butanol, 2-methyl-2-propanol and alcohol X.
5. Record the colour change.

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SK015 & SK025 Lab Manual

(C) Confirmatory test for phenol
1. Dissolve approximately 0.05 g phenol into 2.5 mL of distilled water in a test tube.
2. Add bromine water drop by drop until the bromine colour disappears.
3. Record the observation.
Note: Carry out this test in a fume cupboard.

EXERCISE
1. Explain the formation of the two layers in the Lucas test.
2. Write the equations for all reactions.

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SK015 & SK025 Lab Manual

EXPERIMENT 6 ALDEHYDES AND KETONES

Course Learning Objective

Demonstrate the correct techniques in handling laboratory apparatus and chemicals when carrying
out experiments. (P3, PLO 2, MQF LOD 2)

Learning Outcomes

At the end of this lesson, students should be able to differentiate between aldehydes and
ketones using qualitative analysis:

Student Learning Time (SLT)

Face-to-face Non face-to-face
2 hour 0

Introduction O

Aldehydes and ketones are organic compounds containing carbonyl group, C.

A carbonyl compound forms an orange or a yellow precipitate with Brady’s reagent,

2,4-dinitrophenylhydrazine.

Aldehydes can be differentiated from ketones by using Fehling’s, Schiff’s or Tollens’
reagents. An aldehyde gives a positive result with the above reagents whereas a ketone
does not. The Iodoform test is used to determine whether a carbonyl compound contains
any methyl carbonyl structure. The formation of a yellow precipitate indicates the presence
of the methyl carbonyl group, H3C C .

O

Apparatus Chemical reagents

Stopper Schiff’s reagent
Dropper Fehling’s solution
Test tube 5 % NH3
Boiling tube 10 % NaOH
Water bath
Thermometer 2,4-dinitrophenylhydrazine
Measuring cylinder (5 mL) 0.3 M AgNO3
I2 in KI solution
ethanal
benzaldehyde
propanone

unknown Y

Note : Use distilled or ANALAR grade for propanone

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SK015 & SK025 Lab Manual

Procedure
(A) Brady’s test

1. Place approximately 1 mL of 2,4-dinitrophenylhydrazine into a test tube and add
5 drops of ethanal.

2. Shake the test tubes and heat it in a water bath at 60 – 70C. Observe the
formation of a precipitate.

Note: If there is no precipitate, add 2 mL of distilled water.
3. Repeat step 1 and 2 with benzaldehyde, propanone and unknown Y.

(B) Fehling’s test
1. Place approximately 1 mL of ethanal, benzaldehyde, propanone and unknown Y
in 4 separate test tubes.
2. Add 2 mL of Fehling’s solution in each test tube.
3. Shake the test tubes gently.
4. Heat the mixture in the hot water bath for 15 - 20 minutes.
5. Record the observations.

(C) Tollens’ test
1. Prepare Tollens’ reagent by adding one drop of 10% NaOH to 2 mL of 0.3 M
AgNO3 in a boiling tube.
2. Add 5 % NH3dropwise until the precipitate dissolves.
3. Place approximately 1 mL of ethanal, benzaldehyde, propanone and unknown Y
in separate test tubes.
4. Add 1 mL of Tollens’ reagent to each test tube and shake the mixtures gently.
5. Allow the mixtures to stand for 3 minutes. If there is no change, warm the
mixture in a water bath at 60 – 70C for 5 minutes.
6. Record the observations.

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SK015 & SK025 Lab Manual

(D) Schiff’s test
1. Place approximately 1 mL of ethanal, benzaldehyde, propanone and unknown Y
in separate test tubes.
2. Add 1 to 3 drops of Schiff’s reagent into each of the test tubes.
3. Shake each test tube gently and note the colour change.
4. If any of the compounds does not dissolve, stopper the test tube and shake it
vigorously until an emulsion is formed.
5. Record your observation.

(E) Iodoform test
1. Place 10 drops of I2 in KI solution into 3 mL of distilled water in a boiling tube.
2. Add 5 drops of ethanal into the boiling tube and shake gently.
3. Add 10% NaOH to the boiling tube drop by drop until the colour of the I2 fades.
4. Allow it to stand for 2 to 3 minutes. If no precipitate forms, warm the boiling tube
in a water bath at 60 – 70oC.
5. If the colour of I2 disappears, add more I2 in KI solution until the colour of I2 is
retained. Repeat Step 4.
6. Record the observations.
7. Repeat the above steps with benzaldehyde, propanone and unknown Y.

EXERCISE

1. Deduce the structure of an unknown based on the following observations:
(a) A yellow precipitate with 2,4-dinitrophenylhydrazine.
(b) Silver mirror formed with Tollens’ reagents.
(c) Pinkish purple solution formed with Schiff’s reagent.
(d) A yellow precipitate with a solution of iodine in sodium hydroxide.

2. State the tests that show the reducing property of an aldehyde and a ketone.

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REFER ENCES

Ali, R. (1995) Panduan Amali Kimia Asas, Kursus Pengajian Tinggi Fajar Bakti,
Selangor.

Baum, S.J., Sandwick, R.K. (1994) Laboratory Exercises in Organic and
Biological Chemistry. Prentice Hall. New Jersey. United States of
America.

Beran, J.A. (1996) A Study of Chemical and Physical Changes, 2nd Edition. John
Wiley & Sons Inc. United States of America.

Chemistry Department of University Malaya. (2001) Laboratory Manual
Organic Chemistry (SCES1220). Universiti Malaya. Malaysia.

Ritchie, R. (2000) Revise AS Chemistry. Letts Educational Ltd. United States of
America.

Ryan, L. (1996) Chemistry for You, Stanley Thorpes (Publishers) Ltd. England.

Seager, S.L., Slabaugh, M.R. (2000) Introductory Chemistry for Today, 4th Edition.
Thomson Learning. California. United States of America.

Stanley, A.J. et.al (2000) Discovering Chemistry : A Year-12 Chemistry Text Book.
Openbook Publishers. South Australia, Australia.

Universiti Teknologi Malaysia (2001) Amali Kimia Am, Jawatankuasa Penerbitan
dan Penulisan Fakulti Sains UTM. Penerbit UTM. Malaysia.

Ware, G., Deretic, G. (1995) Senior Chemistry : Practical Manual, Heinemann.
Victoria.

Chang, R. (2005) Chemistry, 8th Edition. MacGraw Hill. United States of
America.

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ACKNOWLEDGEMENTS

The Matriculation Division, Ministry of Education Malaysia wish to thank everyone who has
contributed in shaping and writing this CHEMISTRY LABORATORY MANUAL (12th Edition)
for the One Year Matriculation Programme. Special thanks go to those for their many
valuable suggestions and conscientiousness in completing this manual.

Dr. Hajah Rosnarizah binti Abdul Halim
Director of Matriculation Division

Dr. Shah Jahan bin Assanarkutty
Deputy Director of Matriculation Division (Academic)

Mohd Junaidi bin Abd Aziz
Senior Principal Assistant Director

Reviewers for the 12th Edition: Universiti Malaya
Universiti Malaya
Prof. Dr. Zanariah binti Abdullah Kolej Matrikulasi Melaka
Prof. Dr. Rosiyah binti Yahya Kolej Matrikulasi Negeri Sembilan
Noor Hayati binti Abu Bakar Kolej Matrikulasi Negeri Sembilan
Rusiati binti Md. Som Kolej Matrikulasi Pulau Pinang
Gan Fie Chuen Kolej Matrikulasi Negeri Sembilan
Nor Hayati binti Abu Bakar Kolej Matrikulasi Negeri Sembilan
Dani Asmadi bin Ibrahim Kolej Matrikulasi Negeri Sembilan
Wan Nor Izana binti Wan Mohammad Kolej Matrikulasi Johor
Noor Fatihah binti Zulkeply Kolej Matrikulasi Perak
Khatijah binti Ali Kolej Matrikulasi Selangor
Fauziah binti Ismail Kolej Matrikulasi Selangor
Nor Aziah binti Lazim Bahagian Matrikulasi KPM
Maizuyah binti Omar Bahagian Matrikulasi KPM
Isharae bin Abdul Mosamad Bahagian Matrikulasi KPM
Azliza binti Arshad
Siti Warda binti Selamat

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