Use of Acid, Base and Salt

1. What is the primary chemical reason an acid is classified as 'weak'?

• A) It is always an organic acid.
• B) It does not release any hydrogen ions in water.
• C) It dissociates only partially in water.
• D) It is not harmful to human skin.

2. What type of acid is present in Borhani and curd that aids in digestion?

• A) Ascorbic acid
• B) Lactic acid
• C) Carbonic acid
• D) Acetic acid

3. What is the main limitation of using an indicator like litmus paper compared to measuring pH?

• A) Indicators are much more expensive than pH meters.
• B) Indicators can only identify if a substance is acidic or alkaline, not its exact strength.
• C) Indicators only work for colorless solutions.
• D) The color change in indicators is often permanent and cannot be reversed.

4. How does highly alkaline soil (pH > 9.5) become less fertile?

• A) It loses essential nutrients like calcium and magnesium.
• B) It becomes too dry for plants to absorb water.
• C) It allows harmful aluminium ions to be transported to plant roots.
• D) It kills all beneficial microorganisms instantly.

5. Why is it advised not to use cosmetics designed for adults on newborn babies?

• A) Adult cosmetics are generally more expensive.
• B) The pH of a newborn's skin is near neutral (7), while adult skin is acidic, causing potential damage.
• C) Babies might be allergic to the colors used in adult cosmetics.
• D) Adult cosmetics are not tested for use on babies.

6. What is the pH value of a neutral substance like pure water?

• A) 0
• B) 2.0
• C) 7
• D) 14

7. According to the Women and Child Repression Control Act-1995 of Bangladesh, what is the punishment for acid throwing?

• A) 10 years of imprisonment
• B) A significant financial penalty
• C) Community service
• D) Life time imprisonment or death sentence