Chemical Effects of Current

Q. Electroplating is based on the ______ effect of electric current.

1. magnetic
2. glowing
3. heating
4. chemical

Q. Why does potato becomes green after passing electricity from it?

Q. Explain why copper, though a good conductor of electricity, is a non-electolyte.

Q.

How can you identify the positive terminal of a cell or a battery concealed in a box with the help of a potato? [3 MARKS]

Q. What chemical reaction takes place in the potatoes when the electrical current is being passed through it?

Q. The bubbles of gas at the electrode connected to the positive battery terminal are formed during the electrolysis of the water.

1. oxygen
2. hydrogen
3. water

Q. When two copper wires are planted in a potato and connected to a battery, why greenish blue spot is found only around the wire connected to the positive terminal?

1. Potato gets rotten by the heat.
2. Copper gets electroplated.
3. Copper reacts with air.
4. Starch reacts with air.

Q. During electrolysis of water, $H^{+}$ ions electrons to form hydrogen gas at the electrode connected to terminal of battery.

1. gain
2. lose
3. positive
4. negative

Q.

In which of the following examples chemical effects of electric current is desirable?

1. Production of spark at the electrodes.

2. Deposition of metal on the electrodes.

3. Production of heat.

4. Production of Light.

Q.

Name two metals that are generally used for making wires. Explain their use.

Q. Question 16

Observe which of these two circuits A or B shows the correct observation?

Q. Question 9
Why is a layer of zinc coated over iron?

Q. Identify the chemical effects of electric current from the following.

1. Change in colour of the solution.
2. Deposition of metal on electrodes.
3. Evaporation of chemicals.
4. Formation of bubbles of gas on the electrodes.

Q.

State the color of neutral wire according to international convention.

Q. A greenish-blue spot appears around the wire connected to the terminal of the battery while testing the potato.

1. positive
2. negative
3. neutral

Q.

Question 11

Prepare a list of objects around you, that are electroplated.

Q. Question 8 (ii)
Fill in the blanks.
(b) One of the most common applications of chemical effect of electric current is ___.

Q. The bubbles of gas at the electrode connected to the positive battery terminal are formed during the electrolysis of the water.

1. oxygen
2. hydrogen
3. water

Q. How can you identify the positive terminal of a cell or a battery concealed in a box with the help of a potato?

Q. The bubbles of gas at the electrode connected to the positive battery terminal are formed during the electrolysis of the water.

1. oxygen
2. hydrogen
3. water

Q. A greenish-blue spot appears around the wire connected to the terminal of the battery while testing the potato.

1. positive
2. negative
3. neutral