LESSON PLAN 6

Aim: To extract information from an oral talk; to test different acids and alkalis with pH paper; to use a pH probe to read the exact pH value

Teaching objectives

Content

• The pH scale as a measure of the strength of acids and alkalis
• Use of the pH paper and the pH probe to read the pH

Communication

• Dictogloss: writing a summary from an oral talk
• Interpreting data: the pH scale
• Use of ‘would’ to express a hypothesis

Cognition

• Evaluating and discussing the contents of an oral talk
• Solving problems with the information given in an oral talk
• Using different lab instruments

Outcomes

At the end of the lesson, students will be able to

• take notes while listening to a talk
• share information between the team members
• summarise the main ideas of an oral talk
• apply the information of an oral talk to solve exercises
• perform an experiment from the information of an oral talk
• write a lab report
• organise the results of an experiment in a table
• evaluate the relevant information of an oral talk and to apply it to write a lab report
• know what a strong/weak acid/alkali is
• discuss with his/her partner the information of an oral talk
• use different methods to measure the pH (pH meter, pH paper)

Tasks planned and timing

• The teacher will read a text about the pH scale. The students will have to take notes individually while the text is read. They will be asked to write only the relevant points in the text (10 min)
• The students will be provided with a set of cards showing the paragraphs of the text, and with a handout with exercises. The students will have to glue the cards in order on the handout, and they will have to agree with their partner on the piece of information described in the card. They will have to write this information (10 min)
• Plenary: correction of the previous exercise and discussion about it (10 min)
• Students will be given five beakers with different substances in them. They will be asked to measure the pH of each substance with pH paper and with a pH meter. A table will be provided to record their results. They will have to write the lab report of the experiment, and they will have to complete a diagram about the experiment and about the text previously read (30 min)
• Homework: students will have to solve a problem extracting information from a table.

Resources

• For the dictogloss: sets of cards and handouts for each team; glue
• For the experiment: five beakers containing hydrochloric acid, acetic acid, water, ammonia and sodium hydroxide; pH paper; pH meter
• For the exercises about the experiment: a handout for each student
• For the homework: one photocopy for each student

Assessment

• The lab report will be suitably marked
• In the plenary, the students will be marked according to their participation in the discussion