Lesson Notes By Weeks and Term - Senior Secondary 1

Standard separation techniques for mixtures I

Get it on Google Play
Get it on the Apple App Store
  1. Home
  2. Lesson Notes By Weeks and Term
  3. Senior Secondary 1
  4. Standard separation techniques for mixtures I

Term: 1st Term

Week: 5

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:       

Subject:      Chemistry

Topic:-       Standard separation techniques for mixtures I

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

  1. Outline the classification of substances
  2. Explain Filtration, evaporation, decantation, crystallization and fractional crystallization

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 reviews the previous lesson on chemical industries

Students pay attention

STEP 2

EXPLANATION

He outlines and explains the classification of substances

 

Students pay attention and participates

STEP 3

DEMONSTRATION

He explains Filtration, evaporation, decantation, crystallization and fractional crystallization

Students pay attention and participate

STEP 4

NOTE TAKING

The teacher writes a summarized note on the board

The students copy the note in their books

 

NOTE

STANDARD SEPARATION TECHNIQUES FOR MIXTURES

There are two major classes of substances

  1. Pure substance contain single substance and is not mixed with anything else g white sugar, copper sulfate crystals, distilled water
  2. Mixture contains two or more constituents which can easily be separated by physical method e.g: seawater (salt, water & dissolved solids), milk (fats & dissolved solids)

Separation techniques for mixtures are as follows;

  1. Filtration: by this technique an in soluble solid can be separated from its liquid medium using a filter paper aided by a funnel. The insoluble solid which is left in the filter paper is called the residue while the liquid medium which goes through the filter paper is the filtrate. For example, we can separate the following mixtures by filtration. A mixture of
    1. Calcium carbonate, CaCO3 and water, H2O
    2. sand and water
    3. chaff and juice

       2. Evaporation to Dryness is the separation of dissolved solid from a solution as crystals of salt by evaporating all the liquid off.

       3. Decantation; this is a technique used to separate a mixture of liquid and a solid by carefully pouring out the top clear liquid known as the supernatant leaving behind the solid layer known as sediment.

       4. Crystallization is the separation of dissolved solid from a solution in form of crystals

Steps to crystallization

  1. Heat to saturate or concentrate the solution Cool to crystallize the solute
  2. Filter to obtain crystals
  3. Dry crystals between filter papers
  1. Fractional crystallization: This is the process of separating two or more crystalline solids based on the difference in their solubilities in the same solvent is called fractional crystallization.

 

EVALUATION:    1. List and explain the classes of substances

  1. Write short notes on the following
  2. filtration
  3. evaporation
  4. decantation
  5. crystallization
  6. Fractional crystallization

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively