As shown in the figure, a current is passed through an electrolyte of AgCl . It is observed that 2.68 g of silver is deposited on the cathode in 10 minutes. Determine the heat developed in the 20 resistor during this period. The atomic weight of silver is 107.9 g mol ⁻¹ .

Step-by-step solution

According to Faraday's first law of electrolysis, the mass of the substance deposited is given by: m = ZIt = M nF It Substituting the given values ( m = 2.68 g , M = 107.9 g mol ⁻¹ , n = 1 , F = 96500 C mol ⁻¹ , t = 600 s ): 2.68 = 107.9 1 96500 I 600 I = 2.68 96500 107.9 600 4 A The heat developed in the resistor is given by Joule's law of heating: H = I^2Rt Using R = 20 and t = 600 s : H = (4)^2 20 600 H = 16 12000 = 192000 J H = 1.92 10^5 J 1.9 10^5 J