Lesson Notes By Weeks and Term - Senior Secondary 2

TERM׃ 1^ST TERM

WEEK׃ ONE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:        

Subject: Chemistry

Topic: ALKANOLS

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Identify the functional group of alkanols.
2. Discuss the primary types of alkanols.
3. Identify the general properties of alkanols.
4. Discuss the preparation of alkanols both by fermentation and esterification.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION	TEACHER’S ACTIVITY	STUDENT’S ACTIVITY
STEP 1 INTRODUCTION	The teacher make a  review to the students on how alkanols are formed and the functional group.	Students pay attention
STEP 2 EXPLANATION	He explains the primary types of alkanols	Students pay attention and participates
STEP 3 DEMONSTRATION	He discusses the general properties of alkanols.	Students pay attention and participate
STEP 4 DEMONSTRATION	Teacher explains the industrial preparation of alkanols using fermentation and esterification.	Students pay attention and participate
STEP 5 NOTE TAKING	The teacher writes a summarized note on the board	The students copy the note in their books

 

NOTE

ALKANOLS

Alkanols are a class of organic compounds that contain a hydroxyl (-OH) group attached to a corresponding alkane carbon atom. The hydroxyl group is the functional group of the ALKANOLS as it is responsible for the characteristic chemical properties. Alkanols or alcohols, can be categorized based on the number of carbon atoms attached to the carbon bearing the hydroxyl group. Below are the primary types:

1. Methanol (Methyl alcohol):

   - Chemical Formula: CH₃OH

2. Ethanols (Ethyl alcohol):

   - Chemical Formula: C₂H₅OH

3. Propanols (Isopropyl and n-Propanol):

   - Isopropyl Alcohol (Isopropanol):

     - Chemical Formula: (CH₃)₂CHOH

   - n-Propanol (1-Propanol):

     - Chemical Formula: CH₃CH₂CH₂OH

4. Butanols:

   - Chemical Formula: C₄H₉OH

Properties of alkanols

The general properties of alkanols include;

1. Their ability to form hydrogen bonds due to the hydroxyl group, which affects their physical properties like boiling points.
2. They often have higher boiling points compared to similar-sized alkanes due to these inter-molecular forces.
3. Alkanols are also polar compounds, making them miscible with water to varying degrees.
4. Their reactivity can involve processes like dehydration to form alkenes or oxidation to produce carboxylic acids or ketones, depending on the conditions and reactants involved.

   The general equation for the dehydration of an alkanol (represented here as R-CHOH-R') to form an alkene is:

       

     This equation represents the fermentation of glucose (a common sugar) into ethanol and carbon dioxide.

3. Yeast Catalyst:

   - Yeast enzymes facilitate the conversion of sugars into ethanol and carbon dioxide. The process occurs under anaerobic conditions.

4. Distillation:

   - After fermentation, the ethanol-containing mixture is subjected to distillation to separate and concentrate the ethanol. The resulting product is then further purified.

Industrial Preparation of Methanol by Esterification

The industrial preparation of alkanols by esterification involves the reaction between an alcohol and an organic acid to produce an ester and water. If the ester is subsequently hydrolyzed, it can yield an alkanol. Here's an example of the industrial preparation of methanol by esterification:

EVALUATION: - Write down the functional group for alkanols.       

                            - Identify the primary types of alkanols.

                            - Explain briefly the fermentation of alcohol.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively