From the ions
i] `SO_(4)^(2-) and OH^(1-)`
ii] `Cu^(2) and H^(1+)`
iii] `Ag^(1+) and H^(1+)` state giving reasons which ion is discharged at the respective electrode in each case

Name the ion which is discharged at the electrode at which oxygen is 'evolved during electrol of dil. H_2 SO_4

State in the above reactions a reason for the formation of the respective acids from conc. H_(2)SO_(4)

Electrolysis is an important technique for extraction of metals, and each ion of the solution needs a minimum voltage to get discharged and this value is expressed in terms of discharge potential. For some metal ions the discharge potentials follow the order given below : Li^(+) gt K^(+) gt Ca^(2+) gt Na^(+) gt Mg^(2+) gt Al^(3+) gt Zn^(2+) gt Fe^(2+) gt Ni^(2+) gt H_(3)O^(+) gt Cu^(2+) gt Hg_(2)^(2+) gt Ag^(+) gt Au^(3+) For some anions the discharge potentials are in the order : SO_(4)^(2-) gt NO_(3)^(-) gt OH^(-) gt Br^(-) gt I^(-) When conc. H_(2)SO_(4) is electrolysed with high current using Pt electrodes, the product obtained at anode is :

Electrolysis is an important technique for extraction of metals, and each ion of the solution needs a minimum voltage to get discharged and this value is expressed in terms of discharge potential. For some metal ions the discharge potentials follow the order given below : Li^(+) gt K^(+) gt Ca^(2+) gt Na^(+) gt Mg^(2+) gt Al^(3+) gt Zn^(2+) gt Fe^(2+) gt Ni^(2+) gt H_(3)O^(+) gt Cu^(2+) gt Hg_(2)^(2+) gt Ag^(+) gt Au^(3+) For some anions the discharge potentials are in the order : SO_(4)^(2-) gt NO_(3)^(-) gt OH^(-) gt Br^(-) gt I^(-) The product formed at anode and cathode, when dilute H_(2)SO_(4) is electrolysed are :

Complete the following chemical equation: (i) MnO_(4)^(-)(aq)+s_(2)O_(3)^(2-)(aq)+H_(2)O(I) to (ii) MnO_(4)^(-) +NO_(2)^(-)+H^(+) to State reason for the following : (i) Cu(I) ion is not stable in an aqueous solution. (ii) Unlike Cr^(3+),Mn^(2+),Fe^(3+) and the subsequently other M^(2+) ions of the 3d series of elements, the 4d and the 5d series metals generally do not form stable cationic species.

Select the correct answer from the list given in brackets : The ion which is discharged at the anode during the electrolysis of copper sulphate solutions using copper electrodes as anode and cathode. [Cu^(2+) , OH^(-) SO_(4)^(2-) , H^(+)]

Statement-I: In the Daniel cell, if concentration of Cu^(2+) and Zn^(2+) ions are doubled the emf of the cell will not change. Because Statement-II: If the concentration of ions in contact with the metals is doubled, the electrode potential is doubled.

Assertion: Zn gives H_(2) gas with dil. HCl and dil. H_(2)SO_(4) but not with HNO_3 . Reason : NO_3^- ion is reduced in preference to hydronium ion.

Select the correct answer from the list given in brackets : An aqueous electrolyte consists of the ions mentioned in the list, the ion which could be discharged most readily during electrolysis. [Fe^(2+) , Cu^(2+), Pb^(2+) , H^(+)]

The density of H_(2)SO_(4) ………………………….. in lead storage cell during discharging and calomel electrode is a ……………….. electrode.