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Question
Answer the following in one or two sentences.
Write Nernst equation. What part of it represents the correction factor for nonstandard state conditions?
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Solution
1) For any general reaction, aA + bB → cC + dD
Nernst equation is given by
`"E"_"cell" = "E"_"cell"^circ - "RT"/"nF" "ln" (["C"]^"c" ["D"]^"d")/(["A"]^"a" ["B"]^"b")` OR
`"E"_"cell" = "E"_"cell"^circ - (2.303 "RT")/"nF" log_10 (["C"]^"c" ["D"]^"d")/(["A"]^"a" ["B"]^"b")`
where n = moles of electrons used in the reaction, F = Faraday = 96500 C,
T = temperature in kelvin,
R = gas constant = 8.314 J K-1 mol-1
2) The second term in the Nernst equation is the correction for nonstandard state conditions.
Correction factor is `(2.303 "RT")/"nF" log_10 (["C"]^"c" ["D"]^"d")/(["A"]^"a" ["B"]^"b")`
RELATED QUESTIONS
Choose the most correct option.
The standard potential of the cell in which the following reaction occurs:
H2 (g,1 atm) + Cu2+ (1M) → 2H+ (1M) + Cu(s),
`("E"_"Cu"^circ = 0.34 "V")` is
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.
Under what conditions the cell potential is called standard cell potential?
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 \[\ce{E{^{\circ}_{cell}}}\]
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
What is cell voltage?
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.
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 standard EMF for the cell reaction,
\[\ce{Zn + Cu^{2+} -> Zn^{2+} + Cu}\],
is 1.10 V at 25°C. The EMF of the cell reaction, when 0.1 M Cu2+ and 0.1 M Zn2+ solutions are used at 25°C is:
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.
Calculate the emf of the following cell at 25°C.
Zn(s)|Zn2+(0.08 M) || Cu2+(0.l M) |Cu(s)
E0zn = − 0.76 V, E0cu = 0.36 V.
Write net cell reaction.
Standard potential (E°) of
\[\mathrm{Zn_{(aq)}^{+2}+2e^{-}\longrightarrow Zn_{(s)}~is~-0.76~V}\]
What is standard potential of reaction
\[2\mathrm{Zn}_{(\mathrm{s})}\longrightarrow2\mathrm{Zn}_{(\mathrm{aq})}^{+2}+4\mathrm{e}^{-}\] ?
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?
The cell potential for the following cell notation is approximately:
M(s) | M3+ (aq, 0.01 M) || N2+ (aq, 0.1 M) | N(s)
`E_(M^(3+)//M)^0` = 0.6 V and `E_(N^(2+)//N)^0` = 0.1 V
