The haf reaction occuring in the standard hydrogen electrode "SHE" is 2H+ (aq) +2e- <=> H2...

The haf reaction occuring in the standard hydrogen electrode "SHE" is
2H⁺ (aq) +2e- <=> H₂ (g)

a) What is the EMF for this half-cell?
b) How is the EMF value listed in part (a) above for the standard ydrogen electrode measured?
c) Why do we need a "standard reference electrode" like this hydrogen half-cell?
d) How is SHE used to determine unknown half-cell voltages?

Expert Solution

We know emf of 2H⁺ (aq) +2e- <=> H₂ (g)

This half reaction is 0 V

As we go above the EMV table we find that strength of oxidizing agent is increased.

And strength of reducing agent is decreased.

So value of EMF become more positive as we go above the EMF table.

EMF of Standard hydrogen electrode is set at 0 V or we can say that is reference point. All the EMF values are related to the this half reaction. To measure emf of half cell it become easy when we use the SHE as a reference electrode since SHE has 0 V so whatever measurement we get that is for the half cell.

For example,

We have to measure potential of half cell of Zn then we connect this metal electrode to the SHE and we get EMF. That emf half cell of Zn

We get total cell potential by measuring EMF of cell. We know EMF of SHE is 0 V

so whatever the potential of cell ( total ) that will be the potential of unknown half cell.

queen_honey_blossom answered 1 year ago

a) Consider the following half-reactions: Half-reaction E° (V) F2(g) + 2e- 2F-(aq) 2.870V 2H+(aq) + 2e- H2(g) 0.000V Zn2+(aq) + 2e- Zn(s) -0.763V

13)) a) Consider the following half-reactions: Half-reaction E° (V) F2(g) + 2e- 2F-(aq) 2.870V 2H+(aq) + 2e- H2(g) 0.000V Zn2+(aq) + 2e- Zn(s) -0.763V (1) The weakest oxidizing agent is: enter formula (2) The strongest reducing agent is: (3) The strongest oxidizing agent is: (4) The weakest reducing agent is: (5) Will F-(aq) reduce Zn2+(aq) to Zn(s)? (6) Which species can be reduced by H2(g)? If none, leave box blank. b)) Consider the following half-reactions: Half-reaction E° (V) Ag+(aq) +...

NAD^+(aq)+2H^+(aq)+2e^- --> NADH(aq)+H^+(aq) E= -0.320V Oaloacetate^2-(aq)+2H^+(aq)+2e^- --> malate^2-(aq) E= -0.166V a. Calculate the standard potential for...

NAD^+(aq)+2H^+(aq)+2e^- --> NADH(aq)+H^+(aq) E= -0.320V Oaloacetate^2-(aq)+2H^+(aq)+2e^- --> malate^2-(aq) E= -0.166V a. Calculate the standard potential for the following reaction: Oxaloacetate^2- (aq) +NADH(aq)+H^+(aq) --> malate-(aq)+NAD^+(aq) b. Calculate the equilibrium constant for the reaction at 298K

Reduction half-reaction E∘ (V) Ag+(aq)+e−→Ag(s) 0.80 Cu2+(aq)+2e−→Cu(s) 0.34 Sn4+(aq)+4e−→Sn(s) 0.15 2H+(aq)+2e−→H2(g) 0 Ni2+(aq)+2e−→Ni(s) −0.26 Fe2+(aq)+2e−→Fe(s) −0.45...

Reduction half-reaction E∘ (V) Ag+(aq)+e−→Ag(s) 0.80 Cu2+(aq)+2e−→Cu(s) 0.34 Sn4+(aq)+4e−→Sn(s) 0.15 2H+(aq)+2e−→H2(g) 0 Ni2+(aq)+2e−→Ni(s) −0.26 Fe2+(aq)+2e−→Fe(s) −0.45 Zn2+(aq)+2e−→Zn(s) −0.76 Al3+(aq)+3e−→Al(s) −1.66 Mg2+(aq)+2e−→Mg(s) −2.37 1) Use the table of standard reduction potentials given above to calculate the equilibrium constant at standard temperature (25 ∘C) for the following reaction: Fe(s)+Ni2+(aq)→Fe2+(aq)+Ni(s) 2) Calculate the standard cell potential (E∘) for the reaction X(s)+Y+(aq)→X+(aq)+Y(s) if K = 3.80×10−4. Express your answer to three significant figures and include the appropriate units.

Given: Pb2+(aq)+2e–⇌Pb(s);E°=–0.13 Mg2+(aq)+2e–⇌Mg(s);E°=–2.38V Ag+(aq)+e–⇌Ag(s);E°=0.80V 2H+(aq)+2e–⇌ H2(g);E°=0.00V Under standard-state conditions, which of the following species is the...

Given: Pb2+(aq)+2e–⇌Pb(s);E°=–0.13 Mg2+(aq)+2e–⇌Mg(s);E°=–2.38V Ag+(aq)+e–⇌Ag(s);E°=0.80V 2H+(aq)+2e–⇌ H2(g);E°=0.00V Under standard-state conditions, which of the following species is the best oxidizing agent? a. H b.Mg2+ c. Ag+ d. Pb e. Ag

NO3-(aq)+4H+(aq)+3e->NO(g)+2H2O(l) E=0.96V ClO2(g)+e->ClO2-(aq) E=0.95V Cu2+(aq)+2e->Cu(s) E=0.34V 2H+(aq)+2e->H2(g) E=0.00V Pb2+(aq)+2e->Pb(s) E=-0.13V Fe2+(aq)+2e->Fe(s) E=-0.45V Use appropriate data to...

NO3-(aq)+4H+(aq)+3e->NO(g)+2H2O(l) E=0.96V ClO2(g)+e->ClO2-(aq) E=0.95V Cu2+(aq)+2e->Cu(s) E=0.34V 2H+(aq)+2e->H2(g) E=0.00V Pb2+(aq)+2e->Pb(s) E=-0.13V Fe2+(aq)+2e->Fe(s) E=-0.45V Use appropriate data to calculate E?cell for the reaction. 3Cu(s)+2NO3-(aq)+8H+(aq)->3Cu2+(aq)+2NO(g)+4H2O(l) Express your answer using two decimal places.

Use tabulated electrode potentials to calculate ΔG∘ for the reaction 2K(s)+2H2O(l)→H2(g)+2OH−(aq)+2K+(aq)

A galvanic cell consists of a standard hydrogen electrode and a copper electrode. Suppose that the...

A galvanic cell consists of a standard hydrogen electrode and a copper electrode. Suppose that the copper electrode is immersed in a solution that is 0.1 M NaOH and that it is saturated with Cu(OH)2. Find the cell potential?

The value of the equilibrium constant for the electrochemical reaction MnO4–(aq) + 2H+(aq) + ½Cl2(g) ⇌Mn2+(aq)+...

The value of the equilibrium constant for the electrochemical reaction MnO4–(aq) + 2H+(aq) + ½Cl2(g) ⇌Mn2+(aq)+ ClO3–(aq) +H2O(aq) is 5.88 x10–5. What is the value of the equilibrium constant for the reverse reaction?

Half-reaction E° (V) Hg2+(aq) + 2e- -----> Hg(l) 0.855V Ni2+(aq) + 2e- -----> Ni(s) -0.250V Zn2+(aq)...

Half-reaction E° (V) Hg2+(aq) + 2e- -----> Hg(l) 0.855V Ni2+(aq) + 2e- -----> Ni(s) -0.250V Zn2+(aq) + 2e- -----> Zn(s) -0.763V (1) The weakest oxidizing agent is: ___ enter formula (2) The strongest reducing agent is: ___ (3) The strongest oxidizing agent is:___ (4) The weakest reducing agent is: ___ (5) Will Zn(s) reduce Hg2+(aq) to Hg(l)? _____(yes)(no) (6) Which species can be oxidized by Ni2+(aq)? ___ If none, leave box blank.

Co(s) → Co2+(aq) + 2e Fe2+(aq) + 2e-→ Fe(s) b) Calculate the standard cell potential for...

Co(s) → Co2+(aq) + 2e Fe2+(aq) + 2e-→ Fe(s) b) Calculate the standard cell potential for this voltaic cell. c) Calculate the cell potential for this voltaic cell at 298 K if it is constructed using solutions of 0.14 M Co(NO3)2 and 0.27 M Fe(NO3)2. d) When looking at the magnitude of this potential, what can be concluded about the electrochemical cell?

Question