Select the correct statement if –
E°Mg2+/Mg = –2.4V, E°Sn4+/Sn2+ = 0.1 V, \(E_{MnO_{4}^{-}\, ,H^{+}\,/\,Mn^{+2} }^{\circ}\) = 1.5 V, \(E_{I_{2}\,/\,I^{-}}^{\circ} \)= 0.5 V
Here,
1. | MnO4– is the strongest oxidizing agent and Mg is the strongest reducing agent. |
2. | Sn4+ + 2I– Sn2+ + I2 is a spontaneous reaction. |
3. | Mg2+ + Sn2+ Mg + Sn4+ is a spontaneous reaction. |
4. | Weakest oxidizing agent is Sn4+ and weakest reducing agent is Mn2+. |
The temperature coefficient of a standard Cd–cell is –5.0 10–5 Vk–1 whose emf at 25°C is 1.018 V. During the cell operation, the temperature will –
(1) increase
(2) decrease
(3) either
(4) remains constant
A cell Ag | Ag+ || Cu++ | Cu initially contains 2M Ag+ and 2M Cu++ ions. The charger in cell potential after the passage of 10 amp current for 4825 sec is:
(1) –0.000738 V
(2) –1.00738
(3) –0.0038 V
(4) none
For the cell (at 298 K)
Ag(s) | AgCl(s) | Cl–(aq) || AgNO3(aq) | Ag(s)
Which of the following is correct –
(1) The cell emf will be zero when [Ag+]a = [Ag+]c ([Ag+] in anodic compartment = [Ag+] in cathodic compartment)
(2) The amount of AgCl(s) precipitate in anodic compartment will decrease with the working of the cell.
(3) The concentration of [Ag+] = constant, in anodic compartment during working of cell.
(4) Ecell = E°Ag+ | Ag –E°Cl–|AgCl|Ag
During electrolysis of conc. H2SO4, perdisulphuric acid (H2S2O8), and O2 form in equimolar amount. The amount of H2 that will form simultaneously will be :
1. Thrice that of O2 in moles.
2. Twice that of O2 in moles.
3. Equal to that of O2 in moles.
4. Half of that of O2 in moles.
Which of these ions Cu+, Co3+, Fe2+ is stable in aqueous medium.
Given :E°Cu2+/Cu+ = 0.15 volt ; E°Cu+/Cu = 0.53 V ;E°Co3+/Co2+ = 1.82 V ;
E°Fe3+/Fe2+ = 0.77 V ;E°Fe2+Fe = –0.44 V ;E°O2,H+/H2O = 1.23 V
(1) Cu+, Co3+
(2) Co3+
(3) Cu+
(4) Co3+, Cu+, Fe2+
Calculate the useful work of the reaction Ag(s) + 1/2Cl2(g) AgCl(s)
Given
If = 1 atmand T = 298 K
(1) 110 kJ/mol
(2) 220 kJ/mol
(3) 55kJ/mol
(4) 1000 kJ/mol
Consider the cell Ag(s)|AgBr(s)|Br–(aq)||AgCl(s)|Cl–(aq)|Ag(s) at 25°C. The solubility product constants of AgBr & AgCl are respectively 5 × 10–13 & 1 × 10–10. For what ratio of the concentrations of Br– & Cl–ions would the emf of the cell be zero ?
(1) 1 : 200
(2) 1 : 100
(3) 1 : 500
(4) 200 : 1
Acetic acid has Ka = 1.8 × 10–5 while formic acid had Ka = 2.1 × 10–4. What would be the magnitude of the emf of the cell
Pt(H2) Pt(H2) at 25°C
(1) 0.0315 volt
(2) 0.0629 volt
(3) 0.0455 volt
(4) 0.0545 volt
It is observed that the voltage of a galvanic cell using the reaction M(s) + xH+ Mx+ + H2 varies linearly with the log of the square root of the hydrogen pressure and the cube root of the Mx+ concentration. The value of x is:
1. 2
2. 3
3. 4
4. 5