For the reaction `Ag(CN)_(2)^(-)+Ag^(+)+2CN^(-)`, the equilibrium constant at `25^@C" is "4 xx 10^(-19)`. Calculate the `Ag^(+)` concentration in a solution which was originally 0.1 molar in KCN and 0.03 molar in `AgNO_3`.

Explanation

To solve the problem, we need to analyze the given equilibrium reaction and the initial concentrations of the reactants. Here’s a step-by-step solution:

### Step 1: Write the equilibrium expression
For the reaction:
\[ \text{Ag(CN)}_2^{-} + \text{Ag}^{+} + 2\text{CN}^{-} \]
The equilibrium constant \( K \) is given by:
\[ K = \frac{[\text{Ag}^{+}][\text{CN}^{-}]^2}{[\text{Ag(CN)}_2^{-}]} \]

...