Testing Raindrop Acidity

MATERIALS:

For testing property of red sweet potato powder

· Red sweet potato powder

· Water

· Lemon juice

· Konjac syrup

PROCEDURE:

テキストボックス: Just like red cabbage, red sweet potato powder contains anthocyanin that can indicate ph level of a liquid. You can compare acidity of the rain and tap water when you mix red sweet potato powder on them and add lemon juice. Observe which is redder in color.

Taking it further

1. Try to sprinkle Alkaline water instead of raindrop in red sweet potato powder and flour mix. Notice the color when added by lemon juice. Compare the color to the raindrop.

2. Compare number of raindrops in five minutes exposure in the different time of the day. Example 10:20-10:25 then 10:30 to 10:35 and so on.

Using Red Sweet Potato Powder

1. Mix 200 ml of water and 1/3 tablespoon of red sweet potato powder. Stir very well. Divide the mixture into three containers or glass. Take note of the color of the mixture.

2. Drop lemon juice in first container, water in the second container and Konjac syrup on the third. Notice the difference of color before and after.

1. Mix 2 tablespoon of flour and 2/3 tablespoon of red sweet potato powder in a bowl very well.

2. Use tea strainer in transferring the mixed powder to the small container. The height of the mixed powder from the bottom of the container is at least 1 cm. Close the container.

3. Bring the container outside. Open the lid and expose it to the rain for about 5 minutes. Take it to your room. Shake the container lightly.

4. Separate the grains of raindrop using a tea strainer. Let it dry for 2 hours

Note: You can also make additional mix powder in a separate container following the procedure above to compare the sizes of the raindrops in longer period of time. Let your next containers be exposed in rain for 7 minutes..9 minutes..12 minutes..and so on. Increase the amount of the mix powder if you want to expose it for a longer period of time.

Comparison of raindrop sizes and color for longer time exposure to the rain from 9:36pm to 10:10pm of October 22, 2011 Kushiro-shi.