Question

Exercise 20.105 Part A The cell potential of the following electrochemical cell depends on the pH...

Exercise 20.105

Part A

The cell potential of the following electrochemical cell depends on the pH of the solution in the anode half-cell:
Pt(s)|H2(g,1atm)|H+(aq,?M)||Cu2+(aq,1.0M)|Cu(s).
What is the pH of the solution if Ecell is 370 mV ?

Express your answer using two significant figures.

pH =

SubmitMy AnswersGive Up

Homework Answers

Answer #1

First, lets write the half cell reactions:

2H+ + 2 e- --------> H2 ......(I)

Cu2+ + 2 e- -------------> 2 Cu (s) .........(II)

From Nernst equation, we know

E0cell = E-cell - RT/nF ln Q

where R =8.314 J K−1 mol−1

T =298 K (assuming standard temperature)

F =9.65×104 C mol−1

n = 2 ( from equation II)

Q = rate constant of the reaction

The reaction of the cell is:

Cu2+ + H2 ---------> Cu + 2 H+

So, Q = [Cu][H+]2/ [Cu2+]

Cu being solid , its concentration is unity. Concentration of Cu2+ is 1.0 moles given

For this cell,

E-cell = 0.34 V (From literature)

Hence, putting all the values we get,

0.37 = 0.34 - 0.059 log10 [ H+]

or, -log10 [ H+] = 0.51

or, pH = 0.51 ( pH = -log10 [ H+])

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The cell potential of the following electrochemical cell depends on the pH of the solution in...
The cell potential of the following electrochemical cell depends on the pH of the solution in the anode half-cell: Pt(s)|H2(g,1atm)|H+(aq,?M)||Cu2+(aq,1.0M)|Cu(s). What is the pH of the solution if Ecell is 360 mV ?
1) A constant current of 0.800 A is run through the electrolytic cell in order to...
1) A constant current of 0.800 A is run through the electrolytic cell in order to produce oxygen (gas) at the anode: 2 H2O → O2(g) + 4 e- + 4 H+ The amount (in grams) of O2 obtained after 15.2 min of electrolysis is [X] g 2) Electrolysis of a solution of Tl3+ produces deposition of elemental thallium, Tl, at the cathode. The time (in min.) needed for a constant current of 1.20 A to deposit 0.500 g of...
What is the pH of the solution in the anode compartment of the following cell if...
What is the pH of the solution in the anode compartment of the following cell if the measured cell potential at 25 ∘C is 0.27 V ? Pt(s)|H2(1atm)|H+(?M)||Pb2+(1M)|Pb(s)
Given a potential of 0.456 V, for the following electrochemical cell, what is the concentration of...
Given a potential of 0.456 V, for the following electrochemical cell, what is the concentration of Ag+? Cu2+(aq) (1.0 M)|Cu(s)||Ag+(aq)|Ag(s)
Electrochemical Cell Potentials Table 1: Electrochemical Cell Potentials Cell Measured Total Potential from Multimeter (V)1 Individual...
Electrochemical Cell Potentials Table 1: Electrochemical Cell Potentials Cell Measured Total Potential from Multimeter (V)1 Individual Half-Cell Potentials Cell Reactions5 ΔG (kJ)6 (Cu) Electrode Standard Potential (V)2 Metal Electrode Experimental Potential (V)3 Metal Electrode Theoretical Potential (V)4 Metal Electrode Potential % Error Cu | Sn 0.469 0.34 V 0.34-0.469 =-0.129 Cathode:       Cu2+ + 2e- -> Cu Anode:            Sn ->Sn2++ 2e- Net:          Cu2+ + Sn -> Cu + Sn2+ Cu | Al 0.796 0.34 V 0.34-0.796 =-0.456 Cathode:   Cu2+ +...
What is the calculated value of the cell potential at 298K for an electrochemical cell with...
What is the calculated value of the cell potential at 298K for an electrochemical cell with the following reaction, when the Cu2+ concentration is 1.44 M and the Mg2+ concentration is 1.47×10-4 M ? Cu2+(aq) + Mg(s) Cu(s) + Mg2+(aq) Answer:  V The cell reaction as written above is spontaneous for the concentrations given: _______ true false
When the Cu2+ concentration is 1.40 M, the observed cell potential at 298K for an electrochemical...
When the Cu2+ concentration is 1.40 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 2.805V. What is the Mg2+ concentration? Cu2+(aq) + Mg(s) -----> Cu(s) + Mg2+(aq) Answer: ______M
A pH meter employs a voltaic cell for which the cell potential is very sensitive to...
A pH meter employs a voltaic cell for which the cell potential is very sensitive to pH. A simple (but impractical) pH meter can be constructed by using two hydrogen electrodes: one standard hydrogen electrode and a hydrogen electrode (with 1 atm pressure of H2 gas) dipped into the solution of unknown pH. The two half-cells are connected by a salt bridge or porous glass disk. a)Write the half-cell reactions for the cell. 1) No reaction. 2) H+(aq,1M)+H2O(l)→H3O+(aq), H2(g)→2H+(aq,1M)+2e−. 3)...
Use the standard reduction potentials shown here to answer the questions. Reduction half-reaction E∘ (V) Cu2+(aq)+2e−→Cu(s)...
Use the standard reduction potentials shown here to answer the questions. Reduction half-reaction E∘ (V) Cu2+(aq)+2e−→Cu(s) 0.337 2H+(aq)+2e−→H2(g) 0.000 A copper, Cu(s), electrode is immersed in a solution that is 1.00 M in ammonia, NH3, and 1.00 M in tetraamminecopper(II), [Cu(NH3)4]2+. If a standard hydrogen electrode is used as the cathode, the cell potential, Ecell, is found to be 0.073 V at 298 K. Part A Based on the cell potential, what is the concentration of Cu2+ in this solution?...
A) When the Cu2+ concentration is 1.07 M, the observed cell potential at 298K for an...
A) When the Cu2+ concentration is 1.07 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 1.607V. What is the Mn2+ concentration? Cu2+(aq) + Mn(s)--> Cu(s) + Mn2+(aq) Answer: _____ M B) When the Cu2+ concentration is 5.71×10-4 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 2.609V. What is the Mg2+ concentration? Cu2+(aq) + Mg(s)---> Cu(s) + Mg2+(aq) Answer: _____ M C) When the Cu2+...