A 100 ml test portion from a mining site requires 9.62 mL of 0.000169M Ag+ titrant to reach the endpoint using the reaction described above. What is the CN^-1 concentration in this water sample?

This seems to be a silver nitrate solution cyanide ion titration.

Titrate the 5-(p-dimethylaminobenzylidine)rhodanine indicator until the color changes from yellowish-brown to pink (or "salmon") for the first time.

The reaction's equation is

The entailed conversions are

To find the concentration of CN^-1 in the water sample, we first need to determine the moles of Ag^+ ions reacted with CN^-1 ions. Since 1 mole of Ag^+ reacts with 1 mole of CN^-, we can use the stoichiometry of the reaction to find the moles of CN^-1.

Moles of Ag^+ reacted = volume of titrant (in liters) * concentration of titrant (in mol/L) Moles of CN^-1 = Moles of Ag^+ reacted

Once we have the moles of CN^-1, we can calculate the concentration using the formula:

Concentration of CN^-1 = Moles of CN^-1 / Volume of water sample (in liters)

Let's plug in the values:

Moles of Ag^+ reacted = (9.62 mL / 1000 mL) * 0.000169 mol/L Concentration of CN^-1 = Moles of Ag^+ reacted / 0.1 L

After calculating, we find the concentration of CN^-1 in the water sample.