chemical testing
Post on 23-Jan-2016
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CHEMICAL TESTING
1. Break up about 5 red cabbage leaves into small pieces (about 2cm x 2cm)
2. Put these cabbage pieces into your large cup or jug
3. Ask an adult to pour boiling water into the cup or jug
4. Wait about 5mins for the water to cool and the colour to come out of the cabbage.
5. Pour 5 teaspoons of red cabbage juice into each of the 5 normal sized white or clear cups
HOW TO MAKE RED CABBAGE
INDICATOR FOR YOUR
CHEMICAL TESTING
But before you can test your lemon juice, egg
white, bread soda, white vinegar, and soda
water, you need to know what an acid and
base are!... Next few slides.But before you can test your lemon juice, egg
white, bread soda, white vinegar, and soda
water, you need to know what an acid and
base are!... Next few slides.
PROPERTIES OF ACIDS * Can be corrosive ('burns' your skin) * Sour taste (e.g. lemons, vinegar) * Has a pH less than 7 * Reacts with bases to form salt and water * Reacts with metals to form hydrogen gas * Reacts with carbonates to form carbon dioxide, water and a salt
PROPERTIES OF BASES * Can be corrosive ('burn' your skin) * Bitter taste * Soapy feel * Has a pH more than 7 * Many alkalis (soluble bases) contain hydroxyl ions (OH-) * Reacts with acids to form salt and water
PROPERTIES OF BASES * Can be corrosive ('burn' your skin) * Bitter taste * Soapy feel * Has a pH more than 7 * Many alkalis (soluble bases) contain hydroxyl ions (OH-) * Reacts with acids to form salt and water
Liquids which have a pH of 7 are neither
acidic or basic. They are NEUTRAL. Pure
water is neutral. Your cabbage juice should
be around pH 7. Compare the colour now.
Liquids which have a pH of 7 are neither
acidic or basic. They are NEUTRAL. Pure
water is neutral. Your cabbage juice should
be around pH 7. Compare the colour now.
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