Electrochemistry 1 Question 25
25. In a galvanic cell, the salt-bridge
(2014 Adv.)
(a) does not participate chemically in the cell reaction
(b) stops the diffusion of ions from one electrode to another
(c) is necessary for the occurrence of the cell reaction
(d) ensures mixing of the two electrolytic solutions
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Answer:
Correct Answer: 25. $\left(-11.62 \mathrm{JK} \mathrm{mol}^{-1}\right)$
Solution:
- PLAN This problem is based on characteristics of salt-bridge. Functions of salt-bridge are
(i) It connects the two half-cells and completes the cell circuit.
(ii) It keeps the solutions of two half-cells and complete the cell circuit but does not participate chemically in the cell reaction.
(iii) It maintains the diffusion of ions from one electrode to another electrode.
(iv) A cell reaction may also occur in the absence of salt-bridge. Sometimes, both the electrodes dip in the same electrolyte solution and in such cases we do not require a salt-bridge." So, option (c) is incorrect.
(v) This prevent mixing of two electrolytic solutions hence, option (d) is incorrect choice.
Hence, correct choices are (a), (b).
