Test Yourself : Chapter 3 The ocean

Which of the following shows the steps for extracting common salt (in crystal form) from sea water in the correct sequence?

• A. evaporation → filtration → crystallization
• B. crystallization → evaporation → filtration
• C. filtration → evaporation → crystallization
• D. crystallization → filtration → evaporation

Direction: Questions 2 and 3 refer to the set-up for the distillation of sea water using ‘Quickfit’ apparatus.

Which of the following statements correctly describes the way of cold water flow in the Liebig condenser?

• A. It enters from the upper opening and leaves at the lower opening of the condenser.
• B. It enters from the lower opening and leaves at the upper opening of the condenser.
• C. It enters from the upper opening of the condenser and leaves at the end of the condenser connecting to the receiver adaptor.
• D. It circulates in the lower part of the condenser continuously.

Direction: Questions 2 and 3 refer to the set-up for the distillation of sea water using ‘Quickfit’ apparatus.

The purpose of adding anti-bumping granules to the round-bottomed flask is to

• A. speed up the distillation of sea water.
• B. prevent bumping due to overheating of the sea water.
• C. allow the salts to dissolve in the sea water better.
• D. increase the purity of the distillate collected.

A student used the set-up, as shown in the diagram, for getting common salt from a sample of filtered sea water. Which of the following statements concerning this experiment is/are correct?

(1) The common salt collected is pure.

(2) The common salt collected is in powder form.

(3) A negative result is obtained when the common salt collected is tested by dry cobalt(II) chloride paper.

• A. (1) only
• B. (2) only
• C. (1) and (3) only
• D. (2) and (3) only

Compound W contains potassium and chloride. Which of the combinations of the test results is correct when W is subjected to the flame test and the silver nitrate test respectively?

• A
• B
• C
• D

A student carried out several tests on a sample of sodium chloride solution. Which of the following are the correct observations of these tests?

(1) It gives a brick-red flame in the flame test.

(2) It gives a white precipitate in the silver nitrate test.

(3) It turns anhydrous copper(II) sulphate from white to blue.

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

Direction: Questions 7 and 8 refer to the electrolysis of sea water using the set-up shown in the diagram.

Which of the following statements concerning the electrolysis is/are correct?

(1) Product X can be used in making margarine.

(2) Product Y can be used as a rocket fuel.

(3) Products X and Y can be used to make hydrochloric acid.

• A. (1) only
• B. (2) only
• C. (1) and (3) only
• D. (2) and (3) only

Direction: Questions 7 and 8 refer to the electrolysis of sea water using the set-up shown in the diagram.

Product Z also forms in the electrolysis after some time. Which of the following statements about Z are correct?

(1) It can be used to make drain cleaners.

(2) It can be used to neutralize the acidic effluent discharged by factories.

(3) Products Y and Z can be used to make chlorine bleaches.

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)