When a copper wire is immersed in a solution of AgNO3, the colour of the solution becomes blue because copper:
1. Forms a soluble complex with \(AgNO_3\)
2. Is oxidised to \(Cu^{2+}\)
3. Is reduced to \(Cu^{2-}\)
4. Splits up into atomic form and dissolves
The voltage of the cell given below increases with:
Cell: Sn(s) + 2Ag+(aq) → Sn2+(aq) + 2Ag(s)
1. Increase in size of the silver rod.
2. Increase in the concentration of Sn2+ ions.
3. Increase in the concentration of Ag+ ions.
4. None of the above.
The standard electrode potential for Sn4+/Sn2+ couple is +0.15 V and that for the Cr3+/Cr couple is -0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be:
1. | +0.89 V | 2. | +0.18 V |
3. | +1.83 V | 4. | +1.199 V |
If an iron rod is dipped in CuSO4 solution, then:
1. Blue colour of the solution turns red.
2. Brown layer is deposited on iron rod.
3. No change occurs in the colour of the solution.
4. None of the above.
Without losing it's concentration, ZnCl2 solution cannot be kept in contact with :
1. Au
2. Al
3. Pb
4. Ag
The standard reduction potential for Fe2+|Fe and Sn2+|Sn electrodes are -0.44 V and -0.14 V respectively. For the cell reaction,
Fe2+ + Sn → Fe + Sn2+, the standard Emf is -
1. +0.30 V
2. 0.58 V
3. +0.58 V
4. -0.30 V
Passage of three faradays of charge through an aqueous solution of AgNO3, CuSO4, Al(NO3)3, and NaCl will deposit moles of metals at the cathode in the molar ratio of:
1. | 1 : 2 : 3 : 1 | 2. | 6 : 3 : 2 : 6 |
3. | 6 : 3 : 0 : 0 | 4. | 3 : 2 : 1 : 0 |
Standard Reduction electrode potential of three metals X, Y, and Z are -1.2 V, +0.5 V and -3 V respectively. The reducing power of these metals will be :
1. | Y > X >Z | 2. | Z > X > Y |
3. | X > Y > Z | 4. | Y > Z > X |
A solution containing one mole per litre each of Cu(NO3)2, AgNO3, Hg2(NO3)2 and Mg(NO3)2 is being electrolyzed by using inert electrodes. The values of standard electrode potentials in volt (reduction potentials) are,
Ag+ /Ag = 0.80 V, /2Hg = 0.79 V,
Cu2+/Cu = +0.34 V and Mg2+/Mg = -2.37 V
With increasing voltage, the sequence of deposition of metals on the cathode will be:
1. Ag, Hg, Cu, Mg
2. Mg, Cu, Hg, Ag
3. Ag, Hg, Cu
4. Cu, Hg, Ag
The change in reduction potential of a hydrogen electrode when its solution initialy at pH = 0 is neutralised to pH = 7, is a/an-
1. | Increase by 0.059 V | 2. | Decrease by 0.059 V |
3. | Increase by 0.41 V | 4. | Decrease by 0.41 V |