Strength of Acids and Bases

Q. Give reason for the following:
(d) Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.

Q. Citric acid is a strong acid.

1. True
2. False

Q. For the laboratory preparation of hydrogen, give the following:​ material used.​

Q. Name the impurities present in hydrogen preparation in the laboratory. ​

Q. Give reason for the following:​
Though lead is above hydrogen in the reactivity series, it does not react with dilute hydrochloric acid or dilute sulphuric acid.​

Q. Give reason for the following:​
Potassium and sodium are not used for reaction with dilute hydrochloric acid or dilute sulphuric acid in laboratory preparation of hydrogen.​

Q. In vinegar, water and acetic acid act as solute and solvent, respectively.

1. True
2. False

Q. Choose the weakest acid from the given options.

1. Citric acid
2. Nitric acid
3. Sulphuric acid
4. Hydrochloric acid

Q. An acidic salt is formed by the reaction between a strong acid and a strong base.

1. True
2. False

Q. For the laboratory preparation of hydrogen, give the following:​chemical equation.​

Q. Milk contains citric acid in it.

1. True
2. False

Q. Select the odd one out and justify your answer​
Zn, Fe, Mg and Na

Q. ________ acid is not an example of mineral acid.

1. Nitric
2. Sulphuric
3. Formic
4. Phosphoric

Q. Classify acids based on their sources ? [2 marks]

Q. You are given a 15% solution of sulphuric acid and a 15% solution of HCN (hydrocyanic acid). Which solution has the higher concentration of $H^{+}$ ions?

1. Solution of $H_{2}S{O}_4$
2. Solution of HCN
3. Both have equal concentration
4. Cannot be determined

Q. What are the products formed when $\text{MgO}$ reacts with $\text{HCl}$?

1. ${\text{MgCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}$
2. ${\text{MgCl}}_2\text{(aq)}+{\text{H}}_2\text{O}\text{(l)}$
3. ${\text{MgCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}+{\text{O}}_2\text{(g)}$
4. ${\text{Mg(OH)}}_2\text{(aq)}+{\text{H}}_2\text{O}\text{(l)}+{\text{Cl}}_2\text{(g)}$

Q. An acid which furnishes two $H^{+}$ ions per molecule is called ________ acid.

1. monobasic
2. dibasic
3. tribasic
4. none of the above

Q. When hydrogen is passed over a black solid compound A, the products are 'a colorless liquid' and 'a reddish-brown metal B .’ Substance B is divided into two parts, each placed in separate test tubes.
Dilute HCl is added to one part of substance B and dilute $HN{O}_3$ to the other.​
Is there any reaction between substance B and hydrochloric acid?Give reason for your answer.​

Q. Two test tubes containing water are labelled A and B. A few drops of hydrochloric acid and acetic acid are added to test tube A and test tube B respectively. Which of the following statements are true regarding the number of $H^{+}$ ions in the test tubes?

1. Test tube A has more number of $H^{+}$ ions than test tube B.
2. Test tube B has more number of $H^{+}$ ions than test tube A.
3. Both the test tubes have equal number of $H^{+}$ ions.

Q. The conversion of acetophenone into benzoic acid can be achieved by its reaction with:

1. sodium hydroxide followed by acidification
2. iodine and sodium hydroxide, followed by acidification
3. hydroxylamine followed by reaction with $H_{2}S{O}_4$
4. m-chloroperoxobenzoic acid

Q. Choose the weakest acid from the given options.

1. Sulphuric acid
2. Nitric acid
3. Hydrochloric acid
4. Citric acid

Q. How is the concentration of hydroxide ions ($O{H}^{-}$) affected when the excess base is dissolved in a solution of sodium hydroxide?

Q.

Sulphuric acid when poured over zinc releases ___________ gas.

1. oxygen

2. carbon dioxide

3. hydrogen

4. sulphur dioxide

Q.

Sulphuric acid when poured over zinc releases ___________ gas.

1. hydrogen

2. sulphur dioxide

3. carbon dioxide

4. oxygen

Q. Two test tubes containing water are labeled A and B. A few drops of hydrochloric acid are added to test tube A and acetic acid to test tube B. Which of the following statements are true regarding the number of $H^{+}$ ions in the test tubes?​

Q. ________ acid is not an example of mineral acid.

1. Sulphuric
2. Formic
3. Phosphoric
4. Nitric

Q.

In an experiment, sodium hydroxide solution reacts with hydrochloric acid solution to produce sodium chloride solution and water. Which of the following correctly represents the balanced equation (with physical states) for this experiment?

Q. gas is produced when iron reacts with sulphuric acid.

1. Nitrogen
2. Hydrogen
3. Oxygen

Q. When hydrogen is passed over a black solid compound A, the products are 'a colorless liquid' and 'a reddish-brown metal B.’ Substance B is divided into two parts, each placed in separate test tubes.
Dilute HCl is added to one part of substance B and dilute $HN{O}_3$ to the other.​
Name the substances A and B.​

Q. Choose the correct pairs of the non-metal oxides and the acids formed when they react with water.

1. Nitric acid
2. Carbonic acid
3. Sulphuric acid
4. Nitrogen dioxide
5. Sulphur dioxide
6. Carbon dioxide