Advertisements
Advertisements
प्रश्न
Calculate Ecell and ΔG for the following at 28°C :
Mg(s) + Sn2+( 0.04M ) → Mg2+( 0.06M ) + Sn(s)
E°cell = 2.23V. Is the reaction spontaneous ?
उत्तर
`Mg_(s) + Sn_(aq)^(2+) -> Mg_(aq)^(2+) + Sn_(s)`
`[Sn^(2+)] = 0.04M[Mg^(2+)] = 0.06M`
Q = `[Mg^(2+)]/[Sn^(2+)] = [0.06]/[0.04] = 1.5`
`E_(cell)^(°) = 2.23V`
R = 8.314 JK-1 mol-1
T = 28°C = 28 + 273 = 301K
n = 2
F = 96500 C/mol e-
∴ `E_(cell) = E_(cell)^(°) - [2.303 RT]/[nF] log_10 Q`
= `2.23 - [2.303 xx 8.314 xx 301]/[2 xx 96500] log_10 (1.5)`
= `2.23 - [2.303 xx 8.314 xx 301]/[2 xx 96500] xx (0.1760)`
= 2.23 - 0.005255
`E_(cell)` = -2.2247 V
ΔG = `nFE_(cell)`
ΔG = `-2 xx 96500 xx 2.2247`
ΔG = - 429367 J
∵ ΔG is negative therefore reaction is spontaneous.
APPEARS IN
संबंधित प्रश्न
Draw a neat and well labelled diagram of primary reference electrode.
Arrange the following reducing agents in the order of increasing strength under standard state conditions. Justify the answer
|
Element |
Al(s) |
Cu(s) |
Cl(aq) |
Ni(s) |
|
Eo |
-1.66V |
0.34V |
1.36V |
-0.26V |
Can copper sulphate solution be stored in an iron vessel? Explain.
The standard e.m.f of the following cell is 0.463 V
`Cu|Cu_(1m)^(++)`
What is the standard potential of Cu electrode?
(A) 1.137 V
(B) 0.337 V
(C) 0.463 V
(D) - 0.463 V
Calculate E°cell for the following reaction at 298 K:
2Al(s) + 3Cu+2(0.01M) → 2Al+3(0.01M) + 3Cu(s)
Given: Ecell = 1.98V
Calculate emf of the following cell at 25°C:
\[\ce{Sn/Sn^2+ (0.001 M) || H+ (0.01 M) | H2_{(g)} (1 bar) | Pt_{(s)}}\]
Given: \[\ce{E^\circ(Sn^2+/sn) = -0.14 V, E^\circ H+/H2 = 0.00 V (log 10 = 1)}\]
Calculate emf of the following cell at 25 °C :
Fe|Fe2+(0.001 M)| |H+(0.01 M)|H2(g) (1 bar)|Pt (s)
E°(Fe2+| Fe)= −0.44 V E°(H+ | H2) = 0.00 V
Given the standard electrode potentials,
\[\ce{K+/K}\] = −2.93 V, \[\ce{Ag+/Ag}\] = 0.80 V,
\[\ce{Hg^{2+}/Hg}\] = 0.79 V
\[\ce{Mg^{2+}/Mg}\] = −2.37 V, \[\ce{Cr^{3+}/Cr}\] = −0.74 V
Arrange these metals in their increasing order of reducing power.
Draw a neat and labelled diagram of the lead storage battery.
Galvanic or a voltaic cell converts the chemical energy liberated during a redox reaction to ____________.
Which cell will measure standard electrode potential of copper electrode?
The difference between the electrode potentials of two electrodes when no current is drawn through the cell is called ______.
Using the data given below find out the strongest reducing agent.
`"E"_("Cr"_2"O"_7^(2-)//"Cr"^(3+))^⊖` = 1.33 V `"E"_("Cl"_2//"Cl"^-) = 1.36` V
`"E"_("MnO"_4^-//"Mn"^(2+))` = 1.51 V `"E"_("Cr"^(3+)//"Cr")` = - 0.74 V
Use the data given in below find out which of the following is the strongest oxidising agent.
`"E"_("Cr"_2"O"_7^(2-)//"Cr"^(3+))^⊖`= 1.33 V `"E"_("Cl"_2//"Cl"^-)^⊖` = 1.36 V
`"E"_("MnO"_4^-//"Mn"^(2+))^⊖` = 1.51 V `"E"_("Cr"^(3+)//"Cr")^⊖` = - 0.74 V
The positive value of the standard electrode potential of Cu2+/Cu indicates that:
(i) this redox couple is a stronger reducing agent than the H+/H2 couple.
(ii) this redox couple is a stronger oxidising agent than H+/H2 .
(iii) Cu can displace H2 from acid.
(iv) Cu cannot displace H2 from acid.
Value of standard electrode potential for the oxidation of \[\ce{Cl-}\] ions is more positive than that of water, even then in the electrolysis of aqueous sodium chloride, why is \[\ce{Cl-}\] oxidised at anode instead of water?
Which reference electrode is used to measure the electrode potential of other electrodes?
Assertion: Cu is less reactive than hydrogen.
Reason: `E_((Cu^(2+))/(Cu))^Θ` is negative.
Represent the cell in which the following reaction takes place.The value of E˚ for the cell is 1.260 V. What is the value of Ecell?
\[\ce{2Al (s) + 3Cd^{2+} (0.1M) -> 3Cd (s) + 2Al^{3+} (0.01M)}\]
Which is the correct order of second ionization potential of C, N, O and F in the following?
Standard electrode potential of three metals X, Y and Z are – 1.2 V, + 0.5 V and – 3.0 V, respectively. The reducing power of these metals will be:
The potential of a hydrogen electrode at PH = 10 is
Standard reduction potentials (E°) of Cd2+, respectively which is the strongest reducing agent
The emf of a galvanic cell, with electrode potential of Zn2+ = - 0.76 V and that of Cu2+ = 0.34 V, is ______.
