Experiments

Experiments

Choice of experiments • Glance through the curriculum and assessment guide • E.g. Topic VII Redox Reactions, Chemical Cells and Electrolysis

Choice of experiments • Topic VIII Chemical Reactions and Energy

Assessment to be made • Their written worksheets / reportsand the quiz before the experiment is performed • If possible and manageable, practical skills • Class size (Can ALL get involved?) • Safety first • Bench tidiness

Worksheet / Report ? • When to submit? • Time table arrangement (> or < 2 hours) • Class size • School culture • To mark them, consider holistic approach

Marking criteria

Example: Preparation of salt • Topic in NSS curriculum • Topic IV: Acids and Salts • Total number of periods • 2 × 40 minutes

Example: Students’ manual

Example: Quiz • Classify the following substances into acids, bases and salts. • Classify the salts into the soluble category and the insoluble category. • Use only those chemical reagents listed in question 1, write chemical equations for the preparation of barium sulphate and magnesium sulphate-7-water

Example: Quiz

Example: Experimental worksheet • Worksheet (to be completed in the lessons) • What is the objective of the experiment? • What do you observe when you mix • barium chloride solution with sodium • sulphate solution? • 3. Write chemical equation(s) for this experiment. • 4. Work out the theoretical mass of the salt • that should be obtained. • 5. What is the purpose of washing the residue • with deionized water? • 6. Record your results • Mass of weighting bottle = _______ g • After 1 week, • Mass of weighting bottle + barium sulphate • = _______ g • Mass of barium sulphate = _______ g • What is the mass percentage yield • of barium sulphate? • Basically, answer questions raised in the manual.

Example: Experimental worksheet

Example: Full Report

Example: Report

Example: Full Report

Experiments

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