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.