Question

When an electric current is passed through a cut potato for a considerable time, a coloured spot is formed around one of the electrodes :
(a) What is the colour of the spot?
(b) Around which electrode (positive or negative electrode) the coloured spot is formed?
(c) Which effect of electric current is involved in this case?

Answer 1

Answer:

(a) The spot color is Greenish blue.

(b) The coloured spot is formed around the positive electrode.

(c) This is known as Chemical effect.

Answer 2

(a) The spot color is greenish blue.

(b) The colored spot is formed around the positive electrode.

(c) This is known as Chemical effect.

Explanation:

• In potato, chemical effect of the electric current is observed. When electric current is passed through potato chemical reaction takes place inside potato.
• Copper and zinc is connected with potato which acts as electrode. Here, redox reaction takes place between two metals.
• Due to formation of copper ions, there is formation of greenish blue spot around copper (positive) electrode.
• When the potato is completely rot, then there is no electrical effect in it.
• The electrochemical reaction is given in the equation below:

$\mathrm{Cu}_{(\mathrm{s})}+\mathrm{Zn}^{2+} \longrightarrow \mathrm{Cu}^{2 +}+\mathrm{Zn}_{(\mathrm{s})}$