The equilibrium constant at `278K` for `Cu(s)+2Ag^(o+)(aq) hArr Cu^(2+)(aq)+2Ag(s)` is `2.0xx10^(15)`. In a solution in which copper has displaced, some silver ions from the solution, the concentration of `Cu^(2+)` ions from the solution, the concentration of `Cu^(2+)` ions is `1.8xx10^(-2) mol L^(-1)` and the concentration of `Ag^(o+)` ions is `3.0xx10^(-9) mol L^(-1)`. Is the system at equilibrium?

Answer

A, B

Explanation

Applying the law of chemical equilibrium to the given reaction, we have
`K=([Cu^(2+)(aq)][Ag(s)]^(2))/([Cu(s)][Ag^(o+)(aq)]^(2))`
By convention, putting `[Ag(s)]=1` and `[Cu(s)]=1`
`:. K=([Cu^(2+)(aq)])/([Ag^(o+)(aq)]^(2))`
Putting `[Cu^(2+)]=1.8xx10^(-2) "mol" L^(-1)`
and `[Ag^(o+)]=3.0xx10^(-9) "mol" L^(-1)`
`K=(1.8xx10^(-2))/((3.0xx10^(-9))^(2))=2xx10^(15)`
Which is same as for the reaction in equilibrium. Hence, the given system is in equilibrium.