Question

The yellow colour of turmeric solution in water  turns red in ________ .
1. milk of magnesia
2. lemon water
3. curd
4. toilet cleaner

Answer 1

Correct Answer - Option 1 : milk of magnesia

Concept:

Acid and Base

Acid	Base
Acids are sour in taste.	Bases are bitter in taste and have a soapy feel.
Acids are present in sour fruits, vinegar, toilet cleaner, etc.	Bases are present in neem, clove, soaps, etc.
Acids turn blue litmus paper to red.	Bases turn litmus paper from red to blue.

Explanation:

• Turmeric powder is usually yellowish in color.
• A paste of turmeric when came in contact with a base like baking soda, its color changes to red. 
• So, turmeric is used to identify the presence of a base. 
• Milk of magnesia is a base used to overcome the problem of acidity in our stomach. 
• So, being a base it will turn turmeric solution red. 
• All other options like lemon water, curd and toiler cleaner (hydrochloric acid) are acids. 

The correct option is hence milk of magnesia. 

Indicator	Colour Change in Acidic Solution	Colour Change in Basic Solution
Phenolphthalein	Colourless	Pink
Methyl Orange	Red or Orange	Yellow
Litmus Paper	Red	Blue
Turmeric	Yellow	Red
China Rose	Dark pink	Green