contestada

Consider the following unbalanced oxidation-reduction reactions in aqueous solution:
Ag+(aq)+Li(s)→Ag(s)+Li+(aq)

Fe(s)+Na+(aq)→Fe2+(aq)+Na(s)

K(s)+H2O(l)→KOH(aq)+H2(g)

A)Balance the first reaction.

Express your answer as a chemical equation. Identify all of the phases in your answer.

B)Balance the second reaction.

Express your answer as a chemical equation. Identify all of the phases in your answer.

C)Balance the third reaction.

Express your answer as a chemical equation. Identify all of the phases in your answer.

D)calculate ΔH∘ for each of the reactions.

Express your answers using four significant figures. Enter your answers numerically separated by commas.

E)Based on the values you obtain for ΔH∘ , which of the reactions would you expect to be thermodynamically favored? (That is, which would you expect to be spontaneous?)

F)Use the activity series to predict which of these reactions should occur

G)Are these results in accord with your conclusion in part (e) of this problem?

Respuesta :

Answer:

A) Ag+(aq) + Li(s) = Ag(s) + Na(s)

B) Fe(s) + 2Na+(aq) = Fe2+(aq) + 2Na(s)

C) 2K(s) + 2H2O(I) = 2KOH(aq) + H2(g)

D) ∆H for the above reactions : -384.3KJ/mol, +391.4KJ/mol, -279.9KJ/mol.

E) Reactions A and C would be thermodynamically favored ( spontaneous) because they have negative ∆H values.

F) From the activity series,

I. Lithium is more reactive than silver so can easily displace silver from a solution of silver salt.

II. Iron is less reactive than sodium and cannot easily displace sodium from a solution of sodium salt.

III. Potassium is more electropositive than hydrogen so can easily liberate hydrogen from water.

G) These results are in line with my conclusion in part (E) thus:

I. For reaction (A), ∆H has a high negative value because lithium being highly electropositive easily displaces silver from its aqueous solution, so reaction is spontaneous.

II. For reaction (B), iron being less electropositive than sodium cannot displace it from an aqueous solution hence the very positive ∆H value of the reaction, hence reaction is non-spontaneous.

III. For reaction (C), potassium more electropositive than hydrogen easily displaces it from water hence the high negative ∆H value, hence reaction is spontaneous.

Otras preguntas