Properties of Acids

Q.

Why do we cry during cutting an onion?

Q.

Which type of acid is present in plants and animals?

1. Organic acids

2. Mineral acids

3. Rock acids

4. Inorganic acids

Q. Write the chemical equation for the following reactions: (a) Calcium hydroxide reacts with nitric acid. (b) Acetic acid reacts with calcium. (c) Hydroxide acid reacts with sodium hydroxide. (d) Ammonium hydroxide reacts with sulphuric acid

Q.

When blue litmus paper is dipped into the water the colour of litmus paper remains same. Similarly, when red litmus paper is dipped into the water the colour remains same. By the above observation we can conclude that:

1. Water is acidic.

2. Water is basic.

3. No conclusion can be made.

4. Water is neither acidic nor basic.

Q.

Why is aqua regia called royal water?

Q. Why do we use HCl to remove rust?

Q.

Why is dilute sulphuric acid used in place of concentrated sulphuric acid to prepare copper sulphate?

Q.

An Aqueous solution of sodium carbonate is basic and not acidic. Assign reason.

Q.

Why do some plants and fruits taste sour? [2 MARKS]

Q.

In three test tubes A, B and C, three different liquids namely, distilled water, underground water and distilled water in which a pinch of Calcium sulphate is dissolved, respectively are taken. An equal amount of soap solution is added to each test tube and the contents are shaken. In which test tube will the length of the foam (lather) be longest? Justify your answer.

Q.

Acid rain is caused by excess

1. Production of coal gas

2. Release of CO₂ due to increasing combustion and respiration

3. Release of SO₂ and NO from burning fossil fuels

4. Production of gaseous hydrocarbons

Q.

Sodium hydrogen carbonate on reacting with nitric acid produces ____ and ____

Q. Which of the following is the correct way for the process of dilution of acids?

1. Add water to acid

2. Add acid to water

3. Mix acid and water simultaneously

4. Add water to acid in a shallow container

Q.

While diluting an acid, water should be poured in concentrated acid.

1. True

2. False

Q. Which of the following gases are responsible for acid rain?

1. Carbon dioxide
2. Oxygen
3. Nitrogen gas
4. ozone

Q. What is formed when dilute hydrochloric acid is added to chalk powder (calcium carbonate)? Write the balanced chemical equation for this reaction?

Q.

Statement 1: Acids and bases can be corrosive in nature.

Statement 2: Acids and bases used in our homes are harmless.

1. Both statements are correct.
2. Only statement 2 is correct.
3. Both statements are incorrect.
4. Only statement 1 is correct.

Q.

Zinc reacts with acid to give salt and hydrogen gas.

1. True

2. False

Q.

Permanent hardness of water can be removed by:

1. Boiling

2. Addition of washing soda

3. Addition of potassium permanganate

4. Addition of slaked lime

Q. Why are acids dangerous?

Q.

Why does lemon tastes sour ans tamarind tastes tangy?

Q.

Why is sodium hydrogen carbonate an essential ingredient in antacids?

Q.

The effect of sting of an ant can be neutralized by rubbing with a substance that can neutralize the effect of the sting. Name one such substance. [2 MARKS]

Q. Sushweta makes a drink for which she adds lemon juice to water. The drink will be _______ in taste.

1. sweet
2. bitter
3. sour
4. spicy

Q.

We know that the items which taste sour are acidic , so why lemon juice don't harm having sour taste?

Q. Acids are _________.

1. sour in taste
2. sweet in taste
3. salty in taste
4. bitter in taste

Q.

Oxygen gas burns with a pop-up sound.

1. True
2. False

Q. Hydrogen gas is obtained in the laboratory by:

1. action of dil.$H_{2}S{O}_4$on zinc granules
2. action of dil.$H_{2}S{O}_4$on aluminum.
3. action of dil.$H_{2}S{O}_4$on copper.
4. None of these

Q.

Question 4

Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions, respectively are
(a) red and blue.
(b) blue and red.
(c) pink and colourless.
(d) colourless and pink

Q.

The gas produced when an acid reacts with marble is

1. Hydrogen

2. Oxygen

3. Nitrogen

4. Carbon dioxide