Sample Lesson Plan using a Scientific Inquiry Approach. Introduction

Transcription

1 Sample Lesson Plan using a Scientific Inquiry Approach Introduction The following document presents a lesson plan of the topic of acids and bases taught using a scientific inquiry approach. The lesson takes place over a single class period (40 ). The purpose of this lesson plan is the show how an inquiry oriented lesson can be conducted within the constraints of the Irish Junior Certificate Syllabus.

2 Date: 30/01/2014 Topic: Acids and Bases Previous knowledge/experience: In the previous lesson students would have been given an introduction to acids and bases with students learning a number of examples of acids and bases and being informed of the fact that some acids and bases are harmful and some are not. Even though they do know of specific examples of acids and bases, they do not know how they would test whether an unknown substance is an acid or a base. They would also not know how to test whether an acid or a base is harmful or not. Impact of previous lesson: students had significant prior knowledge of acids in terms of examples of acids. They did however require a lot of probing to come up with examples of bases. Some students struggled with the idea that some acids/bases could be harmful and questioned how someone would know if an acid or a base was harmful. Therefore todays lesson nicely leads on to this as the students will begin learning about the ph scale. This will be finished in the next lesson with a discussion on the ph of water and neutralisation. Aim(s) of lesson: 1. To develop students awareness of how one can test whether a substance is an acid or a base 2. To expand on the topic of acids and bases by delving deeper into the levels of acidity and basicity using the ph scale. Objectives and Assessment Aim Objectives: Students will 1 Design and conduct an investigation to test whether substances are acids or bases List examples of acids and bases Define the purpose of an indicator 2 Develop an investigation to test out the acidity/basicity of varying substances Use a ph scale to determine whether a substance is a strong/weak acid or base Work in groups to carry out the investigation Assessment Whole group discussion and teacher observation Lab copies and questioning Lab Copies and questioning Whole group discussion and feedback from teacher Lab copies and questioning Observation by teacher

3 Subject matter: The lesson will focus on defining what an indicator is used for together with using litmus paper to identify whether a variety of substances are acids or bases. The next part of the lesson will look at the strength of acidity/basicity of substances. Whilst investigations will be carried out concurrently, the remaining part of the lesson will focus on a discussion on indicators and the ph scale separately. Resources: Examples of acids (vinegar, lemon juice, dilute HCL) and bases (Soap, Soda Water, dilute sodium hydroxide), beakers, droppers, litmus paper, universal indicator paper, acetate, OHP, whiteboard Organisation of lesson Time Teacher activity Student activity 2 mins Recap of the Previous Lesson Asks students a number of questions to recap on the material covered in the previous lesson. Students answer questions individually when prompted to by the teacher Possible questions: What is an acid? What is a base? Name one interesting thing we said about an acid? What are examples of acids? What are examples of bases? The teacher now informs students that in todays lesson they will be asked to design investigations around the testing of whether substances are acids/bases and how acidic or basic they are. Students take out their lab copies and note what the lesson will focus on today

4 5 Formulation of the research question Teacher begins a group discussion and scaffolds students to consider what research question will drive the investigations. The teacher puts the possible questions on the board and refines the questions with the help of the students. The research questions should resemble the following: Students put up their hands and when instructed to by the teacher, give their views on what research questions will revolve around this investigation. The students use their prior learning from the previous lesson to help them establish a research question. 1. How can we test a substance to see if it is an acid or a base? 2. How do we know if some substances are stronger acids or bases? Students take note of the accepted research questions in their lab copies. 8 Designing Investigation The teacher shows the students a number of pieces of apparatus and substances (these include equipment that can be used in the investigations and some Red Herrings ) Students look at the apparatus available for the investigation and in pairs work on procedure to test out the research question. They put this sample procedure in their lab copies. The teacher circulates as the students are designing their investigation Students discuss with the teacher why they have decided to do the investigation in the way they did. The teacher then using the students suggestions writes the investigations on an acetate shown using an overhead projector. Students contribute to the design of the procedure as the teacher puts it on the overhead projector. The teacher confirms the procedure that will be used.

5 The teacher asks students to put on their lab goggles, coats and gloves and advises students to be careful as some of the substances can be dangerous. The students put on the required safety gear and listen to the teacher s safety instructions. Conducting Investigations 13 The teacher circulates as the students carry out the investigation and probes their thinking as they are doing this Collecting Data Students carry out the procedure in their pairs. Students first test a number of substances with red paper and then a number of substances with blue paper. Students then test the same substances with the white paper As the students collect the data the teacher discusses the data with students Students make observations and chose their own way of representing the data (i.e on a table or pictorially). The main observations students should not is that red paper stays red in acid and turns blue in a base and vice versa with blue paper (blue paper turns red in acid and stays blue in a base). They should also note that the white paper turns a variety of colours depending on what substance it is put into. Drawing Conclusions 12 The teacher revisits the research questions and asks students to use their data in groups to answer these questions. The teacher leads a discussion on the conclusions. The teacher informs the students that the paper used to test for an acid or base is litmus paper and is an example of an indicator. The teacher asks the students to define what an indicator is based on what they have observed Students draw conclusions which should reflect the following: Red or blue paper can be used to test whether a substance is an acid or a base and it is an example of an indicator

6 The teacher now leads a discussion on what the students observed when they used the other paper. The teacher asks students why they think the paper changes different colours in different substances. The teacher now puts up a powerpoint slide of a ph scale and asks students to now draw conclusions using this scale. The white paper turns different colours when dropped in different substances. The students look at the scale and should come to the conclusion that a strong acid is a different colour to a weak acid and a strong base is a different colour to a weak base. The students take note of these conclusions The teacher asks random students to say one new thing they had learned today Students answer questions when asked by the teacher The teacher then collects the students work and will offer them feedback in the next lesson The teacher ends the lesson by asking students whether they think water is an acid or a base, the teacher advises that this will be covered in the next lesson. Issues for Reflection