Question 21: Which of the following is used for dissolution of gold?
Explanation: Gold is an inert metal and does not react with any acid. Aqua regia is a mixture of nitric acid and hydrochloric acid in 1 : 3 ratio. It is used by goldsmiths to clean ornaments.
Question 22: Which of the following is not a mineral acid?
Explanation: It is an organic acid.
Question 23: Which among the following is not a base?
Explanation: It is ethanol, an organic compound.
Question 24: Which of the following statements is not correct?
Explanation: Oxides of metals are basic in nature, so they cannot give acid or salt on dissolution in water.
Question 25: Match the chemical substances given in Column (A) with their appropriate application given in
|Column A||Column B|
|(A) Bleaching powder||(i) Preparation of glass|
|(B) Baking soda||(ii) Production of H2 and Cl2|
|(C) Washing soda||(iii) Decolourisation|
|(D) Sodium chloride||(iv) Antacid|
Explanation: Bleaching powder is used as bleaching agent. So, we can easily rule out option d. Baking soda is used as an antacid. So, we can zero in on option c.
Question 26: Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper. What would be the colour obtained?
Explanation: This is the colour of pH paper in neutral solution. Reaction between hydrochloric acid and sodium hydroxide will result in neutralization.
Question 27: Which of the following is(are) true when HCl (g) is passed through water?
Explanation: Acid breaks into ions in aqueous solution and gives hydronium ion (H3O+)
Question 28: Which of the following statements is true for acids?
Question 29: Which of the following are present in a dilute aqueous solution of hydrochloric acid?
Explanation: Same as in previous question.
Question 30: Identify the correct representation of reaction occurring during chloralkali process
Explanation: Brine (aqueous solution of common salt) is used in chloralkali process. Chlorine and hydrogen gases are evolved and sodium hydroxide is formed in aqueous solution.
Copyright © excellup 2014