Write correctly balanced equaitons for the following redox reaction. Using half reaction:
a. `H_(2)S+Fe^(3+)rarrFe^(2+)+Sdarr+H^(o+)`
b. `I^(ө)+IO_(3)^(ө)+H^(o+)rarrI_(2)+H_(2)O`
c. `Bi(s)+NO_(3)^(ө)+H^(o+)rarrNO_(2)+Bi^(3+)+H_(2)O`
d. `I^(ө)+O_(2)(g)+H_(2)OrarrI_(2)+overset(ө)OH`
e. `Cu(s)+Au^(o+)rarrAu(s)+Cu^(2+)`

Answer

A

Explanation

a. `H_(2)SrarrSdarr+2H^(o+)+2e^(-)`
`Fe^(3+)+e^(-)rarr^(2+)]xx2`
`ulbar(H_(2)S+2Fe(+3)rarrS+2Fe^(2+)+2H^(+))`
b. `2IO_(3)^(ө)+12H^(o+)+10^(e-)rarrI_(2)+6H_(2)O`
`2I^(ө)rarrI_(2)+2e^(-)]xx5`
`ulbar(2IO_(3)^(ө)+12H^(o+)+10I^(ө)rarr6I_(2)+6H_(2)O)`
or
`ulbar(IO_(3)^(ө)+5I^(ө)+6H^(o+)rarr3I_(2)+3H_(2)O)`
c. `Bi(s)rarrBi^(3+)+3e^(-)`
`2H^(o+)+NO_(3)^(ө)+e^(-)rarrNO_(2)+H_(2)O]xx3`
`ulbar(Bi(s)+3NO_(3)^(ө)+6H^(o+)rarr3NO_(2)+Bi^(3+)+3H_(2)O)`
d.`2I^(ө)rarrI_(2)+2e^(-)]xx2`
`O_(2)+2H_(2)O+4e^(-)rarr4overset(ө)OH`
`ulbar(O_(2)+2H_(2)O+4I^(ө)rarr2I_(2)+4overset(ө)OH)`
e. `Au^(o+)+e^(-)rarrAu(s)]xx2`
`Cu(s)rarrCu^(2+)+2e^(-)`
`ulbar(2Au^(2+)+Cu(s)rarr2Au(s)+Cu^(2+))`.