Question

Hey I need help solving number 28 ignore 27

27. When left open to the atmosphere, wine, which contains 12 % ethanol, begins developing a sour taste. Why does this happen? Use a chemical equation in your explanation. (2) 28. Calculate the standard cell potential for a galvanic cell that features the following reaction. (3) 2Na 2H2Om2NaOH(aq)+ Hzi)

Answer 1

28.

The net cell reaction is

2Na(s) + 2H2O(l) + 2NaOH(aq) + H2(g)

The oxidation half reaction is

Na(s) → Nat(aq) + E' = +2.71 V

The reduction half reaction is

2H2O(1) + 2 + 20 H(aq) + H2(g) E' = -0.828 V

Ecell = ExaNa+ + E200H- H2

Ecell u= 2.71 V - 0.828 V

EL = 1.882 V