Question

Based on these descriptions, write a balanced equation and the corresponding Kc expression for each reversible reaction.

a. Carbonyl fluoride, COF2(g), decomposes into gaseous carbon dioxide and gaseous carbon tetrafluoride.
b. Copper metal displaces Silver(I) Ion from aqueous solution , producing silver metal and an aqueous solution of copper(II) ion.
c. Peroxodisulfate ion , S2O82- , oxides iron (II) ion to iron (III) ion in aqueous solution and it is itself reduced to sulfate ion.

Answer 1

See full explanation.

Step-by-step explanation:

Hello.

In this case, since we apply the law of mass action in order to write the equilibrium expression for each chemical reaction, we proceed as follows:

a. The reaction is:

`2COF_2(g)\rightleftharpoons CO_2(g)+CF_4(g)`

And the equilibrium expression:

`Kc=([CO_2][CF_4])/([COF_2]^2)`

Since all the species are in gaseous phase they are included on the equilibrium expression.

b. The reaction is:

`Cu(s)+Ag^+(aq)\rightleftharpoons Ag(s)+Cu^(2+)(aq)`

And the equilibrium expression:

`Kc=(Cu^(2+))/(Ag^+)`

Since only copper (II) ions and silver (I) ions are in aqueous phase.

c. The reaction is redox and it turns out:

`(S_2O_8)^(2-)+Fe^(2+)\rightleftharpoons Fe^(3+)+(SO_4)^(2-)\\\\S_2^(7+)+2e^-\rightarrow 2S^(6+)\\\\2* (Fe^(2+)\rightarrow Fe^(3+)+1e^-)\\\\\\(S_2O_8)^(2-)(aq)+2Fe^(2+)(aq)\rightleftharpoons 2Fe^(3+)(aq)+2(SO_4)^(2-)(aq)`

And the equilibrium expression:

`Kc=([Fe^(3+)]^2[(SO_4)^(2-)]^2)/([(S_2O_8)^(2-)][Fe^(2+)]^2)`

Since all the species are in aqueous phase.