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Question
The figure shows an electrolyte of AgCl through which a current is passed. It is observed that 2.68 g of silver is deposited in 10 minutes on the cathode. Find the heat developed in the 20 Ω resistor during this period. Atomic weight of silver is 107.9 g/mol−1.
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Solution
Given:-
Mass of silver deposited, m = 2.68 g
Time, t = 10 minutes = 600 s
Using the formula, m = Zit, we get:-
\[2 . 68 \times {10}^{- 3} = \frac{107 . 9 \times {10}^{- 3}}{96500} \times i \times 600\]
\[ \Rightarrow i = \frac{2 . 68 \times 96500}{107 . 9 \times 600}\]
\[ \Rightarrow i = 3 . 99 = 4 A\]
Heat developed in the 20 Ω resistor,
\[H = i^2 Rt\]
\[ \Rightarrow H = \left( 4 \right)^2 \times 20 \times 600\]
\[ \Rightarrow H = 192000 J = 192 kJ\]
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