Natural Indicators

Q.

Is the soap solution acidic basic or neutral? How would you verify it?

Q.

Baking soda turns:

1. Turmeric to red

2. Purple cabbage juice to green

3. Red litmus to red

4. all of above

Q.

A solution changes the colour of turmeric indicator from yellow to red. The solution is

1. Basic

2. Acidic

3. Neutral

4. Either neutral or acidic

Q. When red cabbage extract is added to lime juice then:

1. the solution remains colourless.
2. the solution turns red.

3. False

4. True

Q. Litmus is a indicator which is obtained from ​​.

1. fungi
2. natural
3. synthetic
4. lichens

Q. Which of the following can change the colour of red litmus to blue?

1. Sodium hydroxide
2. Sulphuric acid
3. Vinegar
4. Lemon juice

Q. Mixtures of several indicators are known as the _________ indicator.

1. Semi synthetic
2. Synthetic
3. Universal
4. Mixed

Q.

17 (f). State whether the following are true or false.:

A mixture of tamarind and sugar will taste both sweet and sour.

1. True
2. False

Q. Mixtures of several indicators are known as the _________ indicator.

1. Semi synthetic
2. Synthetic
3. Universal
4. Mixed

Q. Which of the following can change the colour of red litmus to blue?

1. Sodium hydroxide
2. Sulphuric acid
3. Vinegar
4. Lemon juice

Q. A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.
(a) Name the natural indicator present in curry stain.
(b) Explain the changes in colour of this indicator which take place during washing and rinsing the shirt.
(c) What is the nature of soap (acidic/basic) as shown by the indicator present in curry stain?