CLASS VIII CHEMICAL EFFECTS OF ELECTRIC CURRENT

Sugar solution is a good conductor of electricity.

• True

• False

Which one of the following solutions will not conduct electricity?

• lemon juice

• vinegar

• tap water

• vegetable oil

Which of the following statements is incorrect about the conductivity of water?

• Rain water is a good conductor of electricity.
• On addition of table salt, water conducts electricity.
• On addition of lemon juice, water conducts electricity.
• Water becomes a good conductor of electricity when heated.

When current is passed through a mixture of water and lemon juice, bubbles rise from one of the electrodes. The bubbles are rising from the solution because

• of the heating effect of current
• of the chemical effect of current
• current produces magnetic field around the electrodes
• current always produces air bubbles when passed through a liquid

An electric current can produce

• heating effect only.

• chemical effect only.

• magnetic effect only.

• chemical, heating, and magnetic effects.

Which one of the following solutions will not conduct electricity?

• lemon juice

• vinegar

• tap water

• vegetable oil

Which of the following solutions will not make the bulb in Fig 14.2 glow?

(a)

(b)

(c)

(d)

• sodium chlorides

• copper sulphate

• silver nitrate

• sugar solution in diluted water

Which of the following statements is incorrect about the conductivity of water?

• Rain water is a good conductor of electricity.
• On addition of table salt, water conducts electricity.
• On addition of lemon juice, water conducts electricity.
• Water becomes a good conductor of electricity when heated.

Which of the following liquid is not a good conductor of electricity?

• Orange juice
• Tap water
• Vinegar
• Honey

Adding common salt to distilled water makes it

• Good Conductor

• Poor Conductor

• No change

• Both A and B