CKS3: Yr7 Chemistry Unit 1 – Me the the Scientist!

Lesson number: 5. Lesson Title: Indicators

Learning Outcomes Learning Outcome 1: Explain that strength of acids and alkalis can be found by using the . Level 5 Learning Outcome 2: Make your own indicator and pH scale Level 6 How I did

I am working at level .....because ..............................

........................

I am working at level .....because ..............................

........................

Targets I can move up to level…... by

Recall:

…………………

Answer the

I can move up to level…... by ………………………

Connect:

Learning Outcome 3: Explain which indicator is better, litmus paper or universal indicator? Or your own Level 7

I am working at level .....because ..............................

........................

03:51 I can move up to level…... by ……………………… …………………

STARTER

3 QUESTIONS

(answers in the back of your books):

1.What is the name of the type of paper we can use to test if liquids are acid or alkali?

2.What colour paper must we use to test for acid?

3.Is orange juice acid or alkali?

BIG picture

Key Question: How can you tell if a solution is an acid or an alkali?

What skills will you be developing this lesson?

• • • • • • •

HSW- by carrying out an investigation/ Interpreting data/ evaluating an experiment Literacy- by writing explanations using correctly spelt keywords and by writing an instruction sheet Numeracy- by plotting a graph Team work- during a practical investigation Creative thinking- by considering how to work safely in a laboratory Participation- during a practical activity Reflection- through self and peer assessment of each outcome

How is this lesson relevant to every day life?

We need to be able to identify acids and alkalis and their strengths using indicators then take appropriate action to work safely. Quick Discussion: What do you already know?

03:51

Extended Learning

• • • • • •

Extended Learning task:

Giant Spider Diagram: On a large piece of paper draw a large spider diagram.

In the centre of the spider diagram write the words “What I have learnt about acids, alkalis and pH” Write down anything you can remember from this topic e.g. neutralisation and pH scale.

Rules: Write all your information on A4 paper, cut it out and stick it down on the sugar paper at the end. Use lots of colour. Spend no more than 5 minutes on the title.

Draw pictures to go with your writing but only after all the information has been written down.

Due date: Criteria for Level 5: Basic description, basic detail.

Criteria for Level 6: Description with explanation and good level of detail.

Criteria for Level 7: Detailed description and in depth detailed explanation using examples to highlight points made.

03:51

We use a car indicator to show which way we’re going...

What is an indicator?

How can you test a liquid to find if it is an acid or an alkali?

An

indicator

is a special chemical that changes to a different colour in an acid or an alkali.

Litmus paper

and

litmus solution

are examples of indicators.

Litmus is red in acid.

Litmus is blue in alkali.

We use UNIVERSAL INDICATOR to measure pH

What is the pH scale?

The strength of an acid or alkali is measured by the

pH scale

.

Each

universal indicator colour

is given a number called the

pH value

.

Universal indicator can tell you the pH of a solution.

stronger acid stronger alkali

1 2 3 4 5 6

7

8 9 10 11 12 13 14

strong acid weak acid neutral

What is the pH of a weak acid? What is the pH of strong alkali?

weak alkali strong alkali

New Information for Learning Outcome 1

• • •

Visual: Demonstration Audio: Demonstration Kinaesthetic: Class experiment

03:51

Keywords:

Create sentences using the keywords to show that you know what they mean. Put your hand up if there is any key word from the list that you don’t understand.

• Acid • Alkali • pH • Litmus paper • Universal indicator • Strong • weak • safety goggles • safety precautions 03:51

Task 1 (Level 5)

• Task 1:

• use litmus paper to test a range of household substances, to see if they are acid, alkaline or neutral. Test with universal indicator

• Task 1: Extension • Which are the stronger acids and alkalis?

Task 1: Answers

Substance Colour with Blue Litmus Colour with red Litmus Colour with Universal indicator

Demonstrate your Learning for Outcome 1 Apply (L5) Have you recorded your results in a table? How can you tell which substances are strong or weak acids / alkalis?

Create Evaluate Analyse Apply Understand Remember

03:51

I am working at level .... because ...........

Understand (L4) Can you explain how you find out if a solution is a acid or alkali?

Learning Outcome 1: Review To be able to use a indicators to safely test household substances.

Go back to your Learning Outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.

Learning Outcome Learning Outcome 1: How I did Met?

Partly met?

Not met?

Targets How can I improve on Learning Outcome 1?

Level 5 03:51

New Information for Learning Outcome 2

Making your own indicator • • Task 2: Follow instructions on work sheet to make an indicator and come up with your own pH scale • • Task 2: Extension Evaluate how effective your indictor is, compare it to litmus and universal indicator

Making Red Cabbage Indicator

• • • • • • Crush the cabbage with the mortar and pestle.

Add some distilled water and put into a boiling tube.

Put the tube in a beaker with boiling water and leave for 10 mins.

Filter and keep the liquid. Place liquid in 3 test tubes, A, B and C.

Add water to A, acid to B and alkali to C. Record the colour change.

Test litmus paper with the acid and alkali. Record the colour changes

Demonstrate your Learning for Outcome 2 Create Evaluate Apply (L5) Did you: 1. Complete the experiment ?

2. Record results and write a conclusion?

Analyse Apply Understand I am working at level .... because ...........

To get to the next level I need to ...........

Analyse (L6) Did you: 1. Write a sensible conclusion?

2. Could you describe how you could use beetroot to test if a substance is acid or alkali?

Remember

03:51

Learning Outcome 2: Review To make your own indicator to test 3 household substances and compare the results with those of the litmus paper.

Go back to your Learning Outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.

Learning Outcome Learning Outcome 2: How I did Met?

Partly met?

Not met?

Targets How can I improve on Learning Outcome 2?

Level 6 03:51

Review for Remembering

• • • • • Stand up if you have met the lesson outcomes?

If not what do you need to do next in order to meet the outcome? Record this in your diary as part of your homework.

Is there any part of the lesson you think you need to go over again next lesson?

Tell the person next to you three things you have learnt this lesson.

How will you remember this for your exam?

03:51

How can we work out a scale?

How can we tell what colour universal indicator will turn in an acid?

pH Scale

How did you do?

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Learning Activities for Outcome 3 Extension – In your books:

1.

Use you results from all of today’s 2.

experiments Compare how easy they were to

3.

use, how easy the results were to take, how useful the result were

What’s the problem with 4.

measuring the pH here?

Harder: Why is it useful to know the pH of something?

Keywords: Demonstrate your Learning for Outcome 1 Evaluate (L7) Judge Justify Defend Decide Agree Value Prove Check Criticise Recommend Support Test Apply (L5) Use Build Execute Develop Construct Identify Plan Select Solve Organise Apply Model Remember (L3) Who What When Where Why Which How Match Define List Choose Name Spell Tell Describe Create Evaluate Analyse Apply Understand Remember

03:51

Create (L8) Combine construct Develop Imagine Design Change Improve Discuss Create Invent Suppose Put together Make up Synthesise Analyse (L6) Take apart Compare Classify Examine List Distinguish Simplify Theme Conclude Motive Discover Understand (L4) Explain what when where how Rephrase Demonstrate Summarise Contrast Show Predict Compare Clarify Illustrate Categorise

Technician’s list

Household substances Litmus paper Universal indicator Red cabbage, filter paper, three test tubes, a boiling tube a pestle and mortar, distilled water, glass beaker, dilute acid, filter funnel, dilute alkali, safety glasses.

very hot water, 100cm³ measuring cylinder