Question

10. A quinhydrone electrode can be used for the potentiometric determination of pH. The solution that is to be measured is saturated with quinhydrone, which is an equimolar mixture of quinone and hydroquinone. The potential of the solution is measured with a platinum electrode relative to a reference electrode. The reference electrode, for this measurement, consists of a mixture Hg2SO4(s) and Hg(l) (elemental mercury). The mixture is a contact with K2SO4 (0.500 M). The relevant reactions are as follows: [Chemical Structure: Quinone] + 2H+ + 2e- ? [Chemical Structure: Hydroquinone] E0 = + 0.699 V Hg2^2+ + 2e- ? 2Hg(l) E0 = 0.800V Hg2SO4(s) ? Hg2^2+(aq) + SO4^2-(aq) Ksp = 6.5x10^-7 The cell diagram is as follows: Pt | Hg(l), Hg2SO4(s) | K2SO4(0.500M) || H+(?), Quinhydrone(sat) | Pt What is the pH of the solution if the potential of the electrode against a saturated calomel electrode is -0.205V?

          10. A quinhydrone electrode can be used for the potentiometric determination of pH. The solution that is to be measured is saturated with quinhydrone, which is an equimolar mixture of quinone and hydroquinone. The potential of the solution is measured with a platinum electrode relative to a reference electrode.

The reference electrode, for this measurement, consists of a mixture Hg2SO4(s) and Hg(l) (elemental mercury). The mixture is a contact with K2SO4 (0.500 M). The relevant reactions are as follows:

[Chemical Structure: Quinone] + 2H+ + 2e- ? [Chemical Structure: Hydroquinone] E0 = + 0.699 V

Hg2^2+ + 2e- ? 2Hg(l) E0 = 0.800V
Hg2SO4(s) ? Hg2^2+(aq) + SO4^2-(aq) Ksp = 6.5x10^-7

The cell diagram is as follows:
Pt | Hg(l), Hg2SO4(s) | K2SO4(0.500M) || H+(?), Quinhydrone(sat) | Pt

What is the pH of the solution if the potential of the electrode against a saturated calomel electrode is -0.205V?

10. A quinhydrone electrode can be used for the potentiometric determination of pH. The solution that is to be measured is saturated with quinhydrone, which is an equimolar mixture of quinone and hydroquinone. The potential of the solution is measured with a platinum electrode relative to a reference electrode.

The reference electrode, for this measurement, consists of a mixture Hg2SO4(s) and Hg(l) (elemental mercury). The mixture is a contact with K2SO4 (0.500 M). The relevant reactions are as follows:

[Chemical Structure: Quinone] + 2H+ + 2e- ? [Chemical Structure: Hydroquinone] E0 = + 0.699 V

Hg2^2+ + 2e- ? 2Hg(l) E0 = 0.800V
Hg2SO4(s) ? Hg2^2+(aq) + SO4^2-(aq) Ksp = 6.5x10^-7

The cell diagram is as follows:
Pt | Hg(l), Hg2SO4(s) | K2SO4(0.500M) || H+(?), Quinhydrone(sat) | Pt

What is the pH of the solution if the potential of the electrode against a saturated calomel electrode is -0.205V?

Added by Katherine M.

Question

Please give Ace some feedback