Preparing Test Solutions

Procedure

1. Cut enough red cabbage into small pieces to fill the cup.
2. Pour the cabbage pieces into the blender. Then add 4 cups (1000 ml) of distilled water.



3. Blend the water and cabbage.
4. Hold the strainer over the bowl and empty the contents of the blender into the strainer.
5. Pour the cabbage juice from the bowl into the jar and discard the solid pieces of cabbage left in the strainer.
6. Use the tape and marking pen to label the jar "Red Cabbage Indicator."
7. To prevent spoilage, store the indicator in a refrigerator until needed. It should be discarded after seven days.

Starch Solution (1%)

Materials

¹/₂ teaspoon (2.5 ml) cornstarch
1 cup (250 ml) distilled water
small saucepan
1-pint (500-ml) jar with lid

Procedure

1. Mix the starch with 1 tablespoon (15 ml) of the water to form a paste.
2. Boil the remaining water in the saucepan and slowly add the starch paste.
3. Cook for two minutes, stirring constantly. Allow to cool.
4. Pour into the jar and secure the lid.
5. To prevent spoilage, store the indicator in a refrigerator until needed. It should be discarded after seven days.

Brom Thymol Blue

Materials

1-quart (1-liter) jar with lid

1 quart (1 liter) of distilled water

0.1 gram of brom

thymol blue

Procedure

1. Fill the jar with distilled water.
2. Add the brom thymol blue to the jar.
3. Secure the lid and shake the jar to mix. Note: If the solution appears green or yellow, add one drop of household ammonia (one drop at a time) until the indicator appears blue.

Calcium Hydroxide (Limewater)

Materials

2 1-quart (1-liter) glass jars with lids

distilled water

calcium oxide (lime used to make pickles)

masking tape

marking pen

Procedure

1. Fill one jar with distilled water.
2. Add 1 teaspoon (5 ml) of calcium oxide and stir.
3. Secure the lid and allow the solution to stand overnight.
4. Decant (pour off) the clear liquid into the second jar. Be careful not to pour any of the lime that has settled on the bottom of the jar.
5. Secure the lid and keep the jar closed.
6. Use masking tape and a marking pen to label the jar "Limewater."