Advertisements
Advertisements
Question
Answer the following in one or two sentences.
Write Nernst equation. What part of it represents the correction factor for nonstandard state conditions?
Advertisements
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
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.
Under what conditions the cell potential is called standard cell potential?
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"))`
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:
\[\ce{Mg_{(s)} | Mg^{2+}_{( aq)} || Ag^+_{( aq)} | Ag_{(s)}}\]
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 ΔG0 for the following reaction?
\[\ce{Al_{(s)} + Fe^{3+}_{( aq)} -> Al^{3+}_{( aq)} + Fe_{(s)}}\]; \[\ce{E^0_{cell}}\] = +2.43
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?
What is the standard potential of cell, Ni | Ni2+ (1M) || Cu2+ (1 M) | Cu?
If E°Cu = 0.337 V and E°Ni = - 0.236 V.
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?
Write net cell reaction.
Write the value of `(2.303 RT)/F` in the Nernst equation?
Write the four applications of emf series.
Standard potential (E°) of
\[\mathrm{Zn_{(aq)}^{+2}+2e^{-}\longrightarrow Zn_{(s)}~is~-0.76~V}\]
What is standard potential of reaction
\[2\mathrm{Zn}_{(\mathrm{s})}\longrightarrow2\mathrm{Zn}_{(\mathrm{aq})}^{+2}+4\mathrm{e}^{-}\] ?
What is the reduction potential of hydrogen gas electrode when pure hydrogen gas is at 1 atmosphere pressure and platinum electrode is in contact with HCI of pH 2 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
Which from following is CORRECT expression for Ecell of following cell?
\[\ce{Pb_{(s)} | Pb^++_{(1 m)} || Ag^+_{(0.1 m)} | Ag_{(g)}}\] at 25°C?
