question 24 and 25 urgent please reply fast !!

For question 24, kindly refer to the fifth query solved in the following link:
https://www.meritnation.com/ask-answer/question/here-are-a-list-of-q-z-pls-ans-them-brieflyq1-the-number-o/electrochemistry/2883521

Ask remaining query in a separate thread.