Mn(aq) + 8H+(aq) + 5e- Mn2+(aq) + 4H2O(l);=1051V
Cr2O72-(aq) +14H+(aq) + 6e 2Cr3+(aq) + 7H2O(l);=1.38V
Fe3+(aq) + e- Fe2+(aq);=0.77V
Cl2(g) + 2e- 2Cl-(aq); = 1.40V
The incorrect statement regarding the quantitative estimation of aqueous Fe(NO3)2 is -
1. Mn can be used in aqueous HCl
2. Cr2O72- can be used in aqueous HCl
3. MnO-24 can be used in aqueous H2SO4
4. Cr2O72- can be used in aqueous H2SO4
Which of the following is the strongest oxidising agent?
1.
2.
3.
4.
The strongest oxidizing agent in the above equation is:
1.
2.
3.
4.
The standard electrode potential (E°) values of Al3+/ Al, Ag+ / Ag, K+ / K, and Cr3+ / Cr are –1.66 V, 0.80 V, –2.93 V, & –0.79 V respectively. The correct decreasing order of the reducing power of the metals is:
| 1. | Ag > Cr > Al > K | 2. | K > Al > Cr > Ag |
| 3. | K > Al > Ag > Cr | 4. | Al > K > Ag > Cr |
| (a) | \(E_{k^+/K}^o = - 2.93\ V\); \(E_{Ag^+/Ag}^o = 0.80\ V\) |
| (b) | \(E_{Hg^{2+}/Hg}^o = 0.79\ V\); \(E_{Mg^{2+}/Mg}^o = - 2.37\ V\) |
| (c) | \(E_{Cr^{3+}/Cr}^o = -0.74\ V\) |
The correct arrangement of increasing order for reducing power of elements is:
| 1. | \(\mathrm{Ag}<\mathrm{Hg}<\mathrm{Cr}<\mathrm{Mg}<\mathrm{K} \) |
| 2. | \(\mathrm{Ag}>\mathrm{Cr}>\mathrm{Mg}>\mathrm{Hg}>\mathrm{K}\) |
| 3. | \(\mathrm{K}>\mathrm{Mg}<\mathrm{Cr}<\mathrm{Hg}>\mathrm{Ag} \) |
| 4. | \(\mathrm{K}<\mathrm{Mg}<\mathrm{Cr}<\mathrm{Hg}<\mathrm{Ag}\) |
Standard reduction potentials of the half-reactions are given below:
The strongest oxidizing and reducing agents, respectively, are:
1. and
2. and
3. and
4. and
A solution contains Fe2+, Fe3+ and I– ions. This solution was treated with iodine at 35°C. E° for Fe3+/Fe2+ is +0.77 V and E° for I2/2I– = 0.536 V.
The favourable redox reaction is:
1. Fe2+ will be oxidized to Fe3+.
2. I2 will be reduced to I–.
3. There will be no redox reaction.
4. I– will be oxidized to I2.
Standard electrode potentials are:
\(F e^{+ 2} / F e\) , \(E^\circ\) \(=\) \(- 0 .44\)
\(F e^{+ 3} / F e^{+ 2}\), \(E ^\circ\) \(= 0 . 77\)
Choose the correct observation when \(𝐹𝑒^{+2}\) , \(𝐹𝑒^{+3}\) and \(Fe_{(solid)}\) are kept together:
1. increases
2. decreases
3. remains unchanged
4. decreases
The correct statement about the given reaction is-
(CN)2(g) + 2OH-(aq) CN-(aq) + CNO-(aq) + H2O(l)
| 1. | The reaction is an example of a disproportionation reaction. |
| 2. | Hydrogen atom gets oxidized. |
| 3. | Reaction occurs in acidic medium. |
| 4. | None of the above |
The Mn3+ ion is unstable in solution and undergoes disproportionation reaction to give Mn2+, MnO2 and H+ ion. The balanced ionic equation for the reaction is-
| 1. | \(2 \mathrm{Mn}^{3+}{ }_{(\mathrm{aq})}+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}\)→\({\mathrm{MnO}_{2(\mathrm{~s})}+\mathrm{Mn}^{2+}{ }_{(\mathrm{aq})}+4 \mathrm{H}^{+}{ }_{(\mathrm{aq})}}\) |
| 2. | \( \mathrm{Mn^{3+}_{(aq)} + H_2O_{(l)} } \) → \({\mathrm{MnO}_{2(\mathrm{~s})}+\mathrm{2Mn}^{2+}{ }_{(\mathrm{aq})}+4 \mathrm{H}^{+}{ }_{(\mathrm{aq})}}\) |
| 3. | \(5 \mathrm{Mn}^{3+}(\mathrm{aq})+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}\)→\(\mathrm{MnO}_{2(\mathrm{s})}+3 \mathrm{Mn}^{2+}(\mathrm{aq})+4 \mathrm{H}^{+}(\mathrm{aq})\) |
| 4. | \(2 \mathrm{Mn}^{3+}{ }_{(\mathrm{aq})}+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})} \)→\(2 \mathrm{MnO}_{2(\mathrm{s})}+2 \mathrm{Mn}^{2+}{ }_{(\mathrm{aq})}+4 \mathrm{H}^{+}{ }_{(\mathrm{aq})}\) |