Potential for some half cell reactions are given below. On the basis of these mark the correct answer.
(i) `H^(+)(aq) + e^(-) rightarrow (1/2)H^(2)(g)` `E_(cell)^(@) = 0.00V`
(ii) `2H_(2)O(l) rightarrow O_(2)(g) + 4H^(+)(aq) + 4e^(-)`, `E_(cell) = 1.96V`
(iii) `2SO_(4)^(2-)(aq) rightarrow S_(2)O_(8)^(2-)(aq) + 2e^(-), E_(cell)^(@) = 1.96V`

Potential for some half cell reactions are given below. On the basis of these mark the correct answer. (i) H^(+)(aq) + e^(-) rightarrow (1/2)H^(2)(g) E_(cell)^(@) = 0.00V (ii) 2H_(2)O(l) rightarrow O_(2)(g) + 4H^(+)(aq) + 4e^(-) , E_(cell) = 1.23V (iii) 2SO_(4)^(2-)(aq) rightarrow S_(2)O_(8)^(2-)(aq) + 2e^(-), E_(cell)^(@) = 1.96V

Use the standard reduction potentials to determine what is observed at the cathode during the electrolysis of a 1.0 M solution of KBr that contains phenolphthalein. O_(2)(g) + 4H^(+)(aq) + 4e^(-) rightarrow 2H_(2)O(l) E^(@) = 1.23V Br_(2)(l) + 2e^(-) rightarrow 2Br^(-)(aq) E^(@) = 1.07V 2H_(2)O(l) + 2e^(-) rightarrow H_(2)(g) + 2OH^(-) E^(@0 = -0.80V K^(+) (aq) + e^(-) rightarrow K(s) E^(@) = -2.92V

Given the standard reduction potentials, which statement is correct? {:(Cu^(2)(aq) + 2e^(-) rightarrow Cu(s), E^(@) = 0.34V), (2H^(+)(aq) + 2e^(-) rightarrow H_(2)(g), E^(@)= 0.0V), (Cr^(3+)(aq) + 2e^(-) rightarrow Cr(s),E^(@) = -0.73V):}

MnO_(4)^(-) + 8H^(+) + 5e^(-) rightarrow Mn^(2+) + 4H_(2)O , E^(@) = 1.51V MnO_(2) + 4H^(+) + 2e^(-) righarrow Mn^(2+) + 2H_(2)O E^(@) = 1.23V E_(MnO_(4)^(-)|MnO_(2)

MnO_(4)^(-) + 8H^(+) + 5e^(-) rightarrow Mn^(2+) + 4H_(2)O , E^(@) = 1.51V MnO_(2) + 4H^(+) + 2e^(-) righarrow Mn^(2+) + 2H_(2)O E^(@) = 1.23V E_(MnO_(4)^(-)|MnO_(2)