Question

Take a plastic mug, drill two holes at its base and insert carbon electrodes. Connect these electrodes to a 6 volt battery. Fill the mug with water such that the electrodes are immersed. Add a few drops of dilute sulphuric acid to the water. Take two test tubesfilled with water and invert them over the two carbon electrodes. Switch on the current and leave the apparatus undisturbed for some time. 1. What is the ratio in which hydrogen and oxygen are present in water by volume? A. 1:2 B. 1:1 C. 2:1 D. 1:8 2. Which electrodes are used in this activity? A. Graphite B. Diamond C. Copper D. Coke 3. Where is hydrogen gas collected? A. Anode B. Cathode C. At both electrodes D. Hydrogen gas is not evolved in this activity 4. Which of the following is an endothermic process? A. Dilution of sulphuric acid B. Condensation of water vapours C. Respiration in human beings D. Electrolysis​

Answer 1

Answer:

1 C. 2:1

2 A. Cathode

3 B. Cathode

4 D. Electrolysis

Explanation:

Answer 2

Answers to the above multiple-choice questions are:

1. The ratio in which hydrogen and oxygen are present in water by volume is (C.) 2:1

[This activity or experiment is performed for proving a basic theory of water or the ratio of hydrogen to oxygen in the water. This is performed to prove that the ratio of H2O I.e. water is 2:1. The above experiment is known as the electrolysis of water.]

2. The electrodes used in this activity (A.) Graphite

[In the above experiment, a Graphite rod is used as an anode (one of the electrodes). The oxygen O2 gets collected at the anode i.e. graphite rod as the anode is the positive terminal and oxygen is negative. It is used as an anode or electrode in electrolysis because it is a good conductor of electricity and it is insoluble in water.]

3. Hydrogen gas is collected (B.) cathode

[Cathode is the negative terminal of the electrode. Being a positive ion Hydrogen gets attracted to the oppositely charged terminal and hence collected at the cathode.]

4. An endothermic process from the above-given options is (D.) Electrolysis

[Endothermic reaction is a chemical reaction during which heat energy is absorbed. And during electrolysis heat energy is absorbed. In the above, experiment, heat energy is absorbed by water to break down the molecule of water into oxygen and hydrogen ions separately.]