IDENTIFYING ACID, BASE, NEUTRAL SOLUTION BY USING NATURAL INDICATOR (PURPLE CABBAGE)

        I.            LEARNING OBJECTIV

The students are able:

ü  To indentify the properties acid, base, and neural solution

ü  To classify the substance tested into acid, base, and neutral solution

      II.            THEORY

Some colored plants, such as blossoms (hibiscus, bougainvillea, rose, etc), turmeric, mangosteen peel, and purple cabbage can be use as acid base indicators. The extract of these plants can give different color to acid and base solution.

The color of the mangosteen peel extract is purple (in neutral condition). If the extract is dropped on to acid and base solution, while the color changes from purple to blackish blue in base solution. The changing color of the extract can be used as natural indicators.

Another example of natural indicators is the extract of purple cabbage. If it is dropped in acid, base and neural solutions, their color will change.

COLOR OF EXRACT	CHARACTERISTIC OF SOLUTION
DARK RED	STRONG ACIDIC
RED	MODERATE ACIDIC
PURPLISH RED	WEAK ACIDIC
PURPLE	NEUTRAL
GREENISH BLUE	WEAK BASIC
GREEN	MODERATE BASIC
YELLOW	STRONG BASIC

    III.            MATERIALS

1.      Purple Cabbage

2.      Knife

3.      Bowl

4.      Vinegar

5.      Apple juice

6.      Baking Soda

7.      Detergent

8.      5 Glass

9.      Mixer

    IV.            PROCEDURE

1.      Chop the cabbage

2.      Take in a bowl, and soak in hot water, wait 10 minutes

3.      After 10 minute The cabbage to change juice

4.      Take the juice into 5 glass with same volume

5.      Glass A mix with vinegar, glass B mix with apple juice, glass C  not mix anything, glass D mix with baking soda, and Glass E mix with detergent

6.      Mix each glass with mixer

      V.            RESULT

No.	Glass	Situation		color	containing
		Change	Not Change
1	A	V		DARK RED	STRONG ACIDIC
2	B	V		RED	MODERATE ACIDIC
3	C		V	PURPLE	NEUTRAL
4	D	V		GREENISH BLUE	WEAK BASIC
5	E	V		GREEN	MODERATE BASIC

    VI.            CONCLUSION

so, of the four ingredients of vinegar containing strong acidic Apple juice containing a moderate acidic, baking soda containing weak basic and detergents containing moderate basic