Quiz on Acids, Bases, and Salts

What is the nature of ammonia when it turns red litmus blue?

• Acidic

• Neutral

• Basic

• Alkaline

Answer explanation

Ammonia is a basic substance, which means it has a pH greater than 7. When it turns red litmus paper blue, it indicates that it is basic, confirming that ammonia is indeed a basic compound.

From which source is litmus solution obtained?

• Moss

• Lichens

• Algae

• Fungi

Answer explanation

Litmus solution is obtained from lichens, specifically from certain species that contain the dye litmus. This natural indicator changes color in response to pH, making lichens the correct source.

What is the nature of distilled water?

• Acidic

• Basic

• Neutral

• Alkaline

Answer explanation

Distilled water is neutral because it has a pH of 7. It is free from impurities and does not exhibit acidic or basic properties, making it neither acidic nor alkaline.

What is produced during the process of neutralisation?

• Gas and water

• Acid and base

• Salt and gas

• Salt and water

Answer explanation

During neutralisation, an acid reacts with a base to produce salt and water. This is a fundamental chemical reaction, making 'Salt and water' the correct answer.

Which of the following statements is true about sodium hydroxide?

• Is an acid

• Turns red litmus blue

• Is a neutral solution

• Turns blue litmus red

Answer explanation

Sodium hydroxide is a strong base, which means it turns red litmus paper blue, indicating its basic nature. The other statements are incorrect as it is not an acid, not neutral, and does not turn blue litmus red.

What does an antacid do when you suffer from acidity?

• Increases acidity

• Has no effect

• Neutralises excess acid

• Causes inflammation

Answer explanation

An antacid works by neutralising excess acid in the stomach, providing relief from acidity. It does not increase acidity, have no effect, or cause inflammation.

What happens to blue litmus paper when dipped in a basic solution?

• Turns red

• Remains blue

• Turns yellow

• Disappears

Answer explanation

When blue litmus paper is dipped in a basic solution, it remains blue. This is because blue litmus paper indicates a basic environment, while red litmus paper would indicate acidity.

What is the effect of hydrochloric acid on turmeric indicator?

• No change

• Turns yellow

• Turns blue

• Turns red

Answer explanation

Hydrochloric acid, being an acid, reacts with turmeric indicator, causing it to change color. Turmeric turns red in acidic conditions, making 'Turns red' the correct answer.

What is the purpose of neutralising factory waste?

• To increase acidity

• To prevent harm to organisms

• To enhance its color

• To make it more basic

Answer explanation

The purpose of neutralising factory waste is to prevent harm to organisms. This process reduces toxicity and ensures that harmful substances do not negatively impact the environment and living beings.

Which of the following is a natural indicator?

• Salt

• Baking soda

• Vinegar

• Turmeric

Answer explanation

Turmeric is a natural indicator that changes color in response to pH levels, turning yellow in acidic solutions and red in alkaline ones. The other options do not exhibit this property.