Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought...
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Transcript of Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought...
![Page 1: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/1.jpg)
Making our own pH indicators
![Page 2: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/2.jpg)
• We often think of pH indicators as chemicals that can only be bought from chemical suppliers
• In fact, there are natural pH indicators all around us , if we know where to look
![Page 3: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/3.jpg)
Same flowers.. different pH
Can you guess which flowers have been grown in alkaline soil and which have been grown in acidic soil?
![Page 4: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/4.jpg)
Making Our Own Indicator copy
Juice from…
Colour at start
Colour with acid
Colour with alkali
Is this a good
indicator?
Red cabbage
![Page 5: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/5.jpg)
Indicator from red cabbage
• Take some chopped red cabbage and put it into a mortar and pestle
• Add 10ml of water (use a measuring cylinder)
• Grind up the cabbage
Cabbage
10ml of water
Mortar and pestle
![Page 6: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/6.jpg)
Filter the cabbage juice
![Page 7: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/7.jpg)
• Divide the filtered juice evenly between 2 small beakers
• Add a small drop of acid to one …
• And a small drop of alkali to the other
• Note the results in your table
acid
alkali
![Page 8: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/8.jpg)
Indicator from flowers
• Take some flower petals and put them into a mortar and pestle
• Add a small amount of alcohol
• Grind flower petals • Pour the juice
through a strainer
Petals
ethanol
Mortar and pestle
ethanol
Tea strainer
![Page 9: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/9.jpg)
• Divide the strained juice evenly between 2 small beakers
• Add a small drop of acid to one …
• And a small drop of alkali to the other
• Note the results in your table
acid
alkali
![Page 10: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/10.jpg)
• If there is time , repeat the process with different petals or vegetables
• Which juice do you think makes the best indicator?
• Why do you think this ?
![Page 11: Making our own pH indicators. We often think of pH indicators as chemicals that can only be bought from chemical suppliers In fact, there are natural.](https://reader036.fdocuments.in/reader036/viewer/2022081821/56649ea95503460f94bacffb/html5/thumbnails/11.jpg)