a) What other liquids can be used to make the cell?

Question

Make your own cell. 

(OR) 

Draw the diagram of electrolytic cell and explain.

Collect two injection bottles. Cut two 5 cm long bits of thick copper wire. Use sandpaper to scrap about 1 cm of the coating off both ends of the wires. Break open a exhausted dry cell and remove its outer metal covering (made of zinc). Cut two 2 mm wide and 5 cm long strips from this zinc plate. Insert the copper wires and zinc strips into the rubber caps of the injection bottles as shown in figure. Ensure that the copper wire and zinc strips do not touch each other.

Now take a wire and connect the copper wire of one bottle with the zinc plate of the other bottle. Fill both bottles with dilute sulphuric acid. Carefully close the bottles with the caps in which copper wires and zinc strips are inserted. Your cell is ready. 

How will you test it?

Take an LED. Attach two wires to its two terminals. Touch the wire from one terminal to the zinc plate and the wire from other terminal to the copper wire. Did the LED light up ? If not, change the connections vice-versa. Did the LED glow ?

Repeat the above activity using lemon juice, tamarind juice and tomato juice one by one instead of sulphuric acid to make cells.

a) What other liquids can be used to make the cell?

b) Will detergent solution be useful?

c) How does above cell function?

d) Can you compare this cell with dry cell?

e) Which is good one? Why?

Answer 1

a) Acid solutions.

b) Yes, it is useful.

c) After a few seconds of immersion of zinc and copper into dilute sulphuric acid, zinc slowly begins to dissolve in the sulphuric acid. We can see bubbles getting formed on the copper rod. The current is passed from copper rod to zinc rod. Here chemical energy is converted into electric energy by electrolysis method.

d) In the above cell electrolyte is dilute sulphuric acid whereas in dry cell ammonium chloride paste is electrolyte. The electrodes in above cell is copper and zinc, whereas in dry cell it is graphite (carbon) and zinc.

e) Dry cell is better than ordinary Volta cell. The reason dry cell does not have any fluids. So it is easy to carry dry cell compared with volta cell. So dry cell is better than volta cell.