G8-PHY-L8 Chemical Effects of Electric Current

What is the process of depositing a layer of any desired metal on another material by means of electricity called?

• Electroplating
• Electrochemistry
• Electrolysis
• Galvanization

Which of the following liquids would you expect to be the best conductor of electricity?

• Distilled water
• Lemon juice
• Vegetable oil
• Honey

Why is it dangerous to touch an electrical appliance with wet hands?

• Wet hands are better conductors of electricity
• Wet hands are worse conductors of electricity
• Wet hands are insulated from electricity
• Wet hands have no effect on electrical conductivity

What happens when an electric current is passed through a conducting solution?

• Bubbles form on the electrodes
• The color of the solution changes
• Deposits of metal form on the electrodes
• All of the above

Why does a compass needle show deflection when dipped in lemon juice and connected to a battery?

• Lemon juice is a poor conductor of electricity
• Lemon juice is a good conductor of electricity
• Lemon juice is an insulator
• Lemon juice has no effect on magnetic fields

What did Boojho and Paheli discover when they left the wires of a tester inserted into a potato for half an hour?

• The potato was a good conductor of electricity
• The potato was a poor conductor of electricity
• The wire connected to the positive terminal caused a chemical reaction in the potato
• The wire connected to the negative terminal caused a chemical reaction in the potato

Which of the following metals is commonly used for electroplating to prevent corrosion?

• Copper
• Zinc
• Chromium
• Silver

Why is tin used to coat iron in tin cans for food storage?

• Tin is more reactive than iron
• Tin is less reactive than iron
• Tin has a lower melting point than iron
• Tin is more abundant than iron

What is the purpose of adding a few drops of dilute sulfuric acid to the copper sulfate solution in the electroplating activity?

• To increase the conductivity of the solution
• To decrease the conductivity of the solution
• To change the color of the solution
• To dissolve the copper sulfate

Which of the following would you expect to be the poorest conductor of electricity?

• Distilled water
• Tap water
• Lemon juice
• Salt solution