Question

Write balanced net ionic equations for the following reactions in basic solution:
(a) `H_(2)O_(2)(aq)+ClO_(4)^(Ө)(aq) rarr ClO_(2)^(Ө)(aq)+O_(2)(g)`
(b)
( c) `Cu(OH)_(2)(s) + N_(2)H_(4)(aq) rarr Cu(s)+N_(2)(g)`
(d) `MnO_(4)^(Ө) + IO_(3)^(Ө)(aq)rarr MnO_(2)(s) + IO_(4)^(Ө)(aq)`

Answer 1

Correct Answer - A
Basic medium:
a. `overset(4)cancel(4H_(2)O)+4e^(-)-ClO_(4)^(ө)rarrClO_(2)^(ө)+2cancel(H_(2)O)+4overset(ө)cancel(OH)`
`x-8= -1, x-4= -1`
`x=7, x=3`
`2overset(ө)cancel(OH)+H_(2)O_(2)rarrO_(2)+cancel(2e^(-))+cancel(2H_(2)O)]xx2`
`2+2x=0, 2x=0`
`2x= -2`
`ulbar(ClO_(4)^(ө)+2H_(2)O_(2)rarrClO_(2)^(ө)+2O_(2)+2H_(2)O)` ltbr gt b. `overset(ө)cancel(OH)+H_(2)O+Fe(OH)_(2)rarrFe(OH)_(3)+e^(-)+cancel(H_(2)O)]xx3`
`x-2=0, x-3=0`
`x=2,x=3`
`4H_(2)O+3e^(-)+CrO_(4)^(2-)rarr[Cr(OH)_(4)]^(ө)+4overset(ө)OH`
`x-8= -2, x-4= -1`
`x=6`
`ulbar(4H_(2)O+3Fe(OH)_(2)+CrO_(4)^(2-)rarr3Fe(OH)_(3)+[Cr(OH)_(4)]^(ө)+overset(ө)OH)`
c. `4overset(ө)OH+N_(2)H_(4)rarrN_(2)+4cancel(e^(-))+4cancel(H_(2)O)`
`2x+4=0, 2x=0`
`2x= -4`
`2cancel(H_(2)O)+cancel(2e^(-))+Cu(OH)_(2)rarrCu+2H_(2)O+2overset(ө)cancel(OH)]xx2`
`x-2=0`
`x=0`
`x=2`
`ulbar(N_(2)H_(4)+2Cu(OH)_(2)rarrN_(2)+2Cu+H_(2)O)`
d. `4H_(2)O+cancel(3e^(-))+MnO_(4)^(Θ)rarrMnO_(2)+2H_(2)O+4overset(Θ)(O)H]xx2`
`x-8=-1x-4=0`
`x=7` `x=4`
`2overset(Θ)(O)H+cancel(H_(2)O)+IO_(3)^(Θ)rarrIO_(4)^(Θ)+cancel(2e^(-))+2cancel(H_(2)O)]xx3`
`x-6=-1x-8=-1`
`x=5` `x=7`
`underlineoverline(2MnO_(4)^(Θ)+3IO_(3)^(Θ)+H_(2)Orarr2MnO_(2)+3IO_(4^(Θ)+2overset(Θ)H))` 4H_(2)O+cancel(3e^(-))+MnO_(4)^(ө)rarrMnO_(2)+cancel(H_(2)O)+4overset(ө)OH]xx2`
`x-8= -1, x-4=0`
`x=7, x=4`
`2overset(ө)OH+cancel(H_(2)O)+IO_(3)^(ө)rarrcancel(2e^(-))+2cancel(H_(2)O)]xx3`
`x-6=-1,x-8=-1`
`x=5, x=7`
`ulbar(2MnO_(4)^(ө)+3IO_(3)^(ө)+H_(2)Orarr2MnO_(2)+3IO_(4)^(ө)+2overset(OH))`