Question

5. The total entropy of a system and its surroundings always increases for a spontaneous process is a statement bt a) the third law of thermodynamics. b) the second law of thermodynamics c) the law of constant composition d) the law of conservation of matter e) the first law of thermodynamics 6. Which of the following is a redox reaction? 7. A certain electrochemical cell has for its cell reaction Zn Hgo occurring at the anode? Zno Hg Which is the half-reaction 8. Which of the following statements concerning a voltaic cell is are correcet? I Reduction occurs at the cathode 2. A spontaneous reaction generates an electric current in a voltaic cell 3. Without a salt bridge charge buildup will cause the cell reaction to stop b) 2 only d) 1 and 2 e)I,2, and 3 c)3 only a) I only

Answer 1

(5)

(b) Second law of thermodynamics states that total entropy of system and surroundings always increases in spontaneous process.

(6)

a redox reaction is a reaction in which both reduction and oxidation occurs.

(b) in this part Al gets oxidized from state 0 to +3 and H gets reduced from +1 to 0

(7)

Oxidation occurs at anode.

(c) in this part Zn gets oxidized from state 0 to +2

in all other cases it gets reduced.

(8)

(e) oxidation occurs at anode and reduction at cathode, without salt bridge cell reaction will stop after sometime.