Tarnish on tin is the compound SnO. A tarnished tin plate is placed in an aluminum pan of boiling water. When enough salt is added so that the solution conducts electricity, the tarnish disappears. Imagine that the two halves of this redox reaction were separated and connected with a wire and a salt bridge. Part A Calculate the standard cell potential given the following standard reduction potentials: Al3++3e−→Al;E∘=−1.66 V Sn2++2e−→An;E∘=−0.140 V

1.52V

Explanation:

Oxidation half equation:

2Al(s)−→2Al^3+(aq) + 6e

Reduction half equation

3Sn2^+(aq) + 6e−→3Sn(s)

E°cell= E°cathode - E°anode

E°cathode= −0.140 V

E°anode= −1.66 V

E°cell=-0.140-(-1.66)

E°cell= 1.52V

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l

answer; 4 electrons;