Course Content
Matter
OBJECTIVES By the end of this topic, the trainee should be able to 1.Define matter 2.Explain state of matter 3.Distinguish between physical and chemical changes 4.Explain the gas laws
0/4
Atoms , Elements and Compounds
OBJECTIVES By the end of this topic , the trainee should be able to; 1.Define Elements, Compounds and Mixtures 2.Describe the structure of an atom 3.Describe how to determine the Atomic number ,Mass number and Isotopes
0/3
The Periodic Table
OBECTIVES By the end of this topic, the trainee should be able to : 1.State the historical contribution on development of the periodic table 2.Explain the periodic trends of elements and their compounds 3.State the diagonal relationships of the periodic table
0/3
The S-Block Element
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Explain the chemistry of group I and II elements 2.State the application of group I and two elements and their compounds
0/4
Chemical Bonds
OBJECTIVES By the end of these topic, the trainee should be able to 1.Identify different types of bonds 2.Describe their properties
0/2
Chemical Equilibrium
OBJECTIVES By the end of this topic , the trainee should be able to : 1.Define chemical equilibria 2.Explain types of equilibria 3.Determine equilibrium constant 4.Describe factors affecting chemical equilibrium
0/6
Introduction To Organic Chemistry
By the end of this topic , the trainee should be able to : 1.Explain the aspects of organic chemistry 2.Describe hydrocarbons 3.Classify organic molecules explain chemical reactions of simple organic molecules 4.Explain the properties , synthesis and uses of simple organic molecules
0/10
Acids, Bases and Salts
OBJECTIVES By the end of this session , the trainee should be able to : 1.State properties of acids and bases 2.Differentiate between strong and weak acids 3.Explain types and properties of salts
0/2
PH Analysis
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define the term PH 2.Explain the basic theory of PH 3.State the relationship between PH and color change in indicators 4.Explain the term buffer solution 5.Describe the preparation of buffer solutions 6.State the application of buffer solutions
0/5
Sampling and Sample Preparation
OBJECTIVE By the end of this topic, the trainee should be able to : 1.Define the terms used in sample preparation 2.State the importance of sampling 3.Describe the techniques of sampling 4.Describe the procedure for sample pre-treatment 5.State sample storage methods
0/5
Separation Techniques
OBJECTIVES By the end of this topic , the trainee should be able to : 1.Define separation, extraction and purification 2.Describe the separation , extraction and purification techniques 3.Explain the methods of determining purity of substances
0/2
Heating and Cooling Techniques
OBJECTIVES To identify various techniques used for heating and cooling substances in the laboratory
Heating and Cooling Techniques
OBJECTIVES To identify various techniques used for heating and cooling substances in the laboratory
0/1
Distillation Techniques
By end of this topic, Trainee should be able to : 1. Define distilation 2. State and explain various distillation techniques 3. Outline Various distillation techniques 4. Outline the applications of Distillation techniques
0/3
Crystallization Techniques
OBJECTIVES By the end of the topic, the learner should be able to: 1.To define crystallization 2.To describe crystallization process 3.To carry out crystallization procedure
0/1
Solvent Extraction Techniques
OBJECTIVES By the end of the topic, the learner should be able to 1.Define solvent extraction 2.Explain terms used in solvent extraction 3.Describe methods of solvent extraction 4.Describe selection of appropriate solvents for solvent extraction 5.Determine distribution ration 6.Outline factors actors influencing the extraction efficiency 7.Describe Soxhlet extraction
0/1
Chromatography Techniques
OBJECTIVES By the end of this topic, the learner should be able to: 1.Define chromatography techniques 2.Explain terms used in chromatography techniques 3.Describe principles of chromatography techniques 4.Explain types of chromatography techniques 5.Carry out chromatography experiments 6.Determine RF factor 7.Outline electrophoresis
0/6
Titrimetric Analysis
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define terms used in titrimetric analysis 2.Describe types of titrimetric analysis 3.Balance chemical reactions 4.Work out calculations involved in titrimetric analysis
0/6
Redox Titration
Redox Titration is a laboratory method of determining the concentration of a given analyte by causing a redox reaction between the titrant and the analyte. Redox titration is based on an oxidation-reduction reaction between the titrant and the analyte. It is one of the most common laboratory methods used to identify the concentration of unknown analytes. Redox reactions involve both oxidation and reduction. The key features of reduction and oxidation are discussed below.
0/5
Complexiometric Titration
omplexometric Titration or chelatometry is a type of volumetric analysis wherein the colored complex is used to determine the endpoint of the titration. The method is particularly useful for determination of the exact number of a mixture of different metal ions, especially calcium and magnesium ions present in water in solution .
0/5
Gravimetric Analysis
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define gravimetric analysis 2.Describe the principles of gravimetric analysis 3.Describe the steps involved in gravimetric analysis 4.Explain factors affecting gravimetric analysis 5.Describe the equipments and apparatus used in gravimetric analysis 6.Carry out gravimetric analysis
0/8
Calorimetric Analysis
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define terms and units used in thermochemistry 2.Determine enthalpy changes in chemical reactions 3.Determine heat capacity and specific heat capacity 4.Compare calorific values of different materials 5.Determine different heat reactions 6.Apply law of conservation of energy and Hess law in thermochemical calculations
0/4
Chemistry Techniques for Science Laboratory Technicians
About Lesson

Views: 9

Standardization of redox solutions

 EXAMPLE;  0.1M potassium permanganate standardization against sodium oxalate

Sodium oxalate is probably the most important standard substance used in permanganometry. Oxalate is easily oxidized to carbon dioxide, according to the reaction equation:

5Na2C2O4 + 2KMnO4 + 8H2SO4 → 10CO2 + 8H2O + 5Na2SO4 + 2MnSO4 + K2SO4

First portions of titrant added are decolorizing slowly. To speed up reaction at the beginning solution can be heated to about 70°C. However, reaction is catalyzed by the presence of Mn2+ cations, so it gains speed later during titration

Procedure to follow:

  1. Weight exactly about 0.25-0.30g of dry sodium oxalate and transfer it to Erlenmayer flask.
  2. Add 100 mL of distilled water and dissolve solid.
  3. Add 60 mL of 1M sulfuric acid solution.
  4. Heat up the solution to about 70°C.
  5. Titrate adding small volumes of titrant and waiting each time till the solution decolorizes.
  6. Close to titration end point add titrant dropwise, until a faint pink color persists for 30 seconds.

Titration of Potassium Permanganate against Oxalic Acid

Prepare a standard Oxalic acid solution of about 250 ml.

The molecular mass of oxalic acid is calculated by adding the atomic mass of each constituent atom

The molecular mass of H2C2O4.2H2O = 126

Since the weight of oxalic acid that is required to make 1000 ml of 1M solution is 126 g. Hence, the weight of oxalic acid needed to prepare 250 ml of 0.1 M solution     = 126/1000 x 250 x 0.1 = 3.15 g

Determining the Strength of KMnO4 using Standard Oxalic Acid

In this titration, the analyte is oxalic acid and the titrant is potassium permanganate. The oxalic acid acts as a reducing agent, and the KMnO4 acts as an oxidizing agent. Since the reaction takes place in an acidic medium, the oxidizing power of the permanganate ion is increased. This acidic medium is created by the addition of dilute sulfuric acid.

              MnO4+8H++5e−→Mn2++ 4H2O

KMnO4 acts as an indicator of where the permanganate ions are a deep purple colour. In this redox titration, MnO4 is reduced to colourless manganous ions (Mn2+) in the acidic medium. The last drop of permanganate gives a light pink colour on reaching the endpoint. The following chemical equation can represent the reaction that occurs.

Molecular equation

2KMnO4 + 3H2SO4→K2SO4 + 2MnSO4  +3H2O+5[O]

H2C2O4.2H2O+[O]→2CO2+3[H2O]×5

Complete Reaction

2KMnO4+3H2SO4+5H2C2O4.2H2O→K2SO4+2MnSO4+18H2O+10CO2

Ionic equation

MnO4+8H++5e→Mn2++4H2O]×2

C2O2−4→2CO2 +  2e]×5

Complete Reaction

               2MnO4+16H++5C2O2−4→2Mn2++8H2O + 10CO2

From the above-balanced chemical reaction, it can be observed that 2 moles of KMnO4 reacts with 5 moles of oxalic acid

Join the conversation

You cannot copy content of this page