Question

In the reaction between `HNO_2` and `HCN`: `HNO_2(aq) + CN^(-)(aq) rightleftharpoons HCN(aq) + NO_2^(-)(aq)`, K = `1 x 10^6`. What are the predominate species after the reaction reaches equilibrium?

Answer 1

Which side do you think is favoured by the equilibrium?

Explanation:

For `A+BrightleftharpoonsC+D`, we define `K_"eq"=([C][D])/([A][B])`

If `K_"eq"` is LARGE, which it most certainly is, then it follows that the quotient `([C][D])/([A][B])` is also large, and this means that the concentrations of `C` and `D`, the PRODUCTS are favoured at equilibrium.

Given that the following reaction has reached equilibrium:

`HNO_2(aq) + N-=C^(-)rightleftharpoonsNO_2^(-) + HC-=N(aq)`,

.............it follows that there are large concentrations of `HC-=N` and `"nitrite anion"`.

Why would you NOT want to be downwind of this reaction?