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Safety in the Lab What is different about this classroom and every other classroom in your school?

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Presentation on theme: "Safety in the Lab What is different about this classroom and every other classroom in your school?"— Presentation transcript:

1 Safety in the Lab What is different about this classroom and every other classroom in your school?

2 Safety in the Lab Do you think there are any special rules that apply to a Science Classroom? Can you write 5 down please

3 Safety in Science How to use a Bunsen burner safely How do use chemicals safely

4 Indicator To accurately make an indicator and test how well it works

5 Acids and Alkalis What are they? Where are they used? How do we know if something is an acid or an alkali?

6 Universal indicator has a range of colours that show how weak or strong the acid or alkali is. stronger alkali stronger acid What is the colour for a weak acid? What is the colour for a strong alkali? weak alkali weak acid strong alkali neutral strong acid Telling the difference between solutions- Are they an acid or an alkali?

7 INDICATORS

8 How can you get the red dye out of the cabbage looking at the equipment I have and the equipment in the science room?

9 Indicators AIM- To make an indicator Apparatus : Red Cabbage Hydrochloric acid droppers Sodium Hydroxide droppers Test Tubes White Tiles Various different substances to be tested for their pH (lemonade, vinegar, lemon, bleach etc) Household substances as well as scientific solutions (calcium hydroxide, nitric acid, sulphuric acid). Pipetters

10 Method Place some red cabbage in a 250 ml beaker Add 50 ml of water to the beaker Heat up under a Bunsen burner until the dye appears Pour 1ml in to 2 test tubes Test each test tube with an acid and an alkali What colour does it go in acids? What colour does it go in alkalis?

11 RESULTS SUBSTANCECOLOUR IN INDICATOR

12 Higher Tier Experiment Write Up Aim: To test the effect of different substances on the colour of the red cabbage indicator. Independent Variable: Dependent Variable: Control Variables:

13 Variables Experiment: Independent Variable: Dependent Variable: Control Variables:

14 How can you measure the strength of an acid or an alkali?

15 INDICATORS Can you name any indicators?

16 The strength of an acid or alkali is measured by the pH scale. What is 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. What is the pH of a weak acid? What is the pH of strong alkali? weak alkali weak acid strong alkali strong acid stronger alkali stronger acid neutral

17 Indicators Litmus- Methyl Orange- Universal Indicator- Red Cabbage-

18 The strength of an acid or alkali is measured by the pH scale. What is 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. What is the pH of a weak acid? What is the pH of strong alkali? weak alkali weak acid strong alkali strong acid stronger alkali stronger acid neutral

19 INDICATOR QUESTIONS 1.What colour will Litmus go when added to orange juice? 2.What colour will methyl orange go in Sodium Hydroxide? 3.What colour will Red Cabbage go in Hydrochloric Acid? 4.What colour does toothpaste turn Universal Indicator? 5.What colour would methyl orange go in Vinegar? 6.What colour will Litmus go in Acid Rain? 7.What colour will Litmus go in Sodium Bicarbonate? 8.What colour will Universal Indicator go in tap water? 9.What colour will Methyl Orange go in Soap? 10.What colour does red cabbage go in Nitric Acid?


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