C7.5 Chemical cells and batteries

Question 1

How can you use a difference in the reactivity of metals to make electrical cells and batteries?

Answer 1

➢ If you join 2 metals together by a wire and dip them into an electrolyte - electrons will flow through the wire from zinc to copper

Question 2

Why is a voltage produced because of the reactivity of the elements?

Answer 2

➢ More reactive metal donates electrons - so it acts as the negative terminal of the cell
➢ The current will flow in the circuit from negative to positive

Question 3

The greater the difference in the reactivity between the 2 metals used..?

Answer 3

➢ The higher the voltage produced

Question 4

➢ Why are batteries non-rechargeable?

Answer 4

➢ Once one of the reactants has run out - the cell stops working and should be disposed

Question 5

What affects the voltage produced in a voltmeter?

Answer 5

➢ Difference in the reactivity of the 2 metals

➢ What type of electrolyte solution there is

Question 6

How does a rechargeable batter work?

Answer 6

➢ In the recharging process - the battery is connected to a power supply that reverses the reactions that occur at each electrode when the cell is discharging
➢ This regenerates the original reactants