Advertisements
Advertisements
Question
Answer the following in brief.
Construct a galvanic cell from the electrodes Co3+ | Co and Mn2+/Mn. \[\ce{E{^{\circ}_{Co}}}\] = 1.82 V, \[\ce{E{^{\circ}_{Mn}}}\] = –1.18 V. Calculate \[\ce{E{^{\circ}_{cell}}}\]
Advertisements
Solution
Given:
\[\ce{E{^{\circ}_{Co}}}\] = 1.82 V,
\[\ce{E{^{\circ}_{Mn}}}\] = –1.18 V.
To find: \[\ce{E{^{\circ}_{cell}}}\] and cell representation
Formulae: `"E"_"cell"^circ = "E"_"Cathode"^circ - "E"_"anode"^circ`
Calculation: Electrode reactions are
At anode: \[\ce{3(Mn_{(s)} -> Mn{^{2+}_{(aq)}} + 2e-}\]
At cathode: \[\ce{2(Co{^{3+}_{(aq)}} + 3e- -> Co_{(s)})}\]
The cell is composed of Mn (anode), Mn(s) \[\ce{Mn{^{2+}_{(aq)}}}\] and Co (cathode), \[\ce{Co{^{3+}_{(aq)}} | Co_{(s)}}\]
The cell is represented as:
\[\ce{Mn_{(s)} | Mn{^{2+}_{(aq)}} || Co{^{3+}_{(aq)}} | Co_{(s)}}\]
The standard electrode potential is given by
\[\ce{E{^{\circ}_{cell}} = E{^{\circ}_{cathode}} - E{^{\circ}_{anode}}}\]
= 1.82 V – (–1.18 V)
= 1.82 V + 1.18 V
= 3.00 V
The standard cell potential is 3.00 V.
RELATED QUESTIONS
Consider the half reactions with standard potentials.
- \[\ce{Ag^{\oplus}_{ (aq)} + e^{\ominus} -> Ag_{(s)}E^\circ = 0.8 V}\]
- \[\ce{I2_{(s)} + 2e^\ominus -> 2I^{\ominus}_{(aq)} E^\circ = 0.53V}\]
- \[\ce{Pb^{2\oplus}_{(aq)} + 2e^{\ominus} -> Pb_{(s)} E^\circ = -0.13 V}\]
- \[\ce{Fe^{2\oplus} + 2e^{\ominus} -> Fe_{(s)} E^\circ = -0.44 V}\]
The strongest oxidising and reducing agents respectively are ______.
Answer the following in one or two sentences.
What is standard cell potential for the reaction
\[\ce{3Ni_{(s)} + 2Al^{3+} (1M) → 3Ni^{2+} (1M) + 2Al(s)}\], if `E_"Ni"^circ` = –0.25 V and `"E"_("Al")^circ` = –1.66 V?
Answer the following in one or two sentences.
Write Nernst equation. What part of it represents the correction factor for nonstandard state conditions?
Answer the following:
Calculate emf of the cell:
Zn(s) |Zn2+ (0.2 M)||H+ (1.6 M)| H2(g, 1.8 atm)| Pt at 25 °C.
Calculate emf of the cell at 25°C.
Zn(s) | Zn2+ (0.08 M) || Cr3+ (0.1 M) | Cr(s)
`E_(Zn)^0` = −0.76 V, `E_(Cr)^0` = −0.74 V
Answer the following:
Predict whether the following reaction would occur spontaneously under standard state condition.
`"Ca"_(("s")) + "Cd"_(("aq"))^(2+) -> "Ca"_(("aq"))^(2+) + "Cd"_(("s"))`
Answer the following:
Predict whether the following reaction would occur spontaneously under standard state condition.
`2"Br"_(("aq"))^(-) + "Sn"_(("aq"))^(2+) -> "Br"_(2("l")) + "Sn"_(("s"))`
What is cell voltage?
Calculate the voltage of the cell Sn(s) / Sn2+(0.02 M) // Ag+ (0.01 M) / Ag(s) at 25 °C.
Given: `"E"_"Sn"^circ` = - 0.136, `"E"_"Ag"^circ` = 0.800 V
Calculate `"E"_"cell"^circ` of the following galvanic cell:
Mg(s) / Mg2+(1 M) // Ag+ (1 M) / Ag(s) if `"E"_"Mg"^circ` = – 2.37 V and `"E"_"Ag"^circ` = 0.8 V. Write cell reactions involved in the above cell. Also mention if cell reaction is spontaneous or not.
Standard reduction electrode potentials of three metals A, B and C are +0.5 V, −3.0 V and −1.2 V respectively. The reducing power of these metals is ______.
Nernst equation for the following cell reaction at 298 K is:
\[\ce{Mg_{(s)} | Mg^{2+}_{( aq)} || Ag^+_{( aq)} | Ag_{(s)}}\]
Calculate E.M.F. of following cell at 298 K Zn(s) |ZnSO4 (0.01 M)| |CuSO4 (1.0 M)| Cu(s) if \[\ce{E^0_{cell}}\] = 2.0 V.
Calculate \[\ce{E^0_{cell}}\] for the following cell.
\[\ce{Cr_{(s)} | Cr^{3+}_{( aq)} || Fe^{2+}){( aq)} | Fe_{(s)}}\]
Given: `"E"_("Cr"^(3+)//"Cr")^0` = −0.74 V,
`"E"_("Fe"^(2+)//"Fe")^0` = −0.44 V
The reduction potential of a half-cell consisting of nickel electrode in 0.1 M NiSO4 solution at 25°C is ____________.
(E0 = −0.257 V)
Identify the strongest reducing agent from the data given below:
| Element | `"E"^0 ("V")` |
| Al | −1.66 |
| Fe | −0.44 |
| Hg | +0.79 |
| Cu | +0.337 |
What is the standard emf of the following cell?
\[\ce{Ni_{(s)} | Ni^{2+}_{( aq)} || Au^{3+}_{( aq)} | Au_{(s)}}\]
if \[\ce{E^0_{Ni}}\] = −0.25 V, \[\ce{E^0_{Au}}\] = 1.50 V.
For the following cell, standard potential of copper electrode is 0.337 V and standard cell potential is 0.463 V.
\[\ce{Cu | Cu^{2+} (1 M) || Ag^+ (1 M) Ag}\]
What is the standard potential of silver electrode?
The tendency of an electrode to lose electrons is known as ______
The standard potential of the cell in the following reaction is ______.
\[\ce{Cd_{(s)} + Cu^{2+}_{(1M)} -> Cd^{2+}_{(1M)} + Cu_{(s)}}\]
`("E"_("Cd")^circ = - 0.403V, "E"_("Cu")^circ = 0.334V)`
Which element from the following has the highest negative standard reduction potential?
Construct a cell from Ni2+ | Ni and Cu2+ | Cu Cu half cells. Write the cell reaction and calculate `E_("cell")^0`
`(E_("Ni")^0 = - 0.236 V and E_("Cu")^0 = + 0.337 V)`
The standard potential of the electrode Zn2+(0.02M) |Zn(s) is − 0.76 V. Calculate the electrode potential of the zinc electrode.
Write net cell reaction.
If \[\mathrm{E^o\left(Cd_{(aq)}^{+2}|Cd_{(s)}\right)=-0.40~V}\]. What is potential for \[\mathrm{Cd}_{(s)}\xrightarrow{}\mathrm{Cd}_{(aq)}^{+2}\left(0.01\mathrm{M}\right)+2\mathrm{e}^{-}\] at 298 K?
