Why is Solid PbI2 is yellow ,yet a solution of the salt in water is colourless?

1 Answer
May 4, 2018

Refer to the explanation.

Explanation:

The solution does not contain lead iodide PbI2. Typically, you would mix together a solution of lead nitrate Pb(NO3)2, which is colorless, and another solution such as potassium iodide KI, which is also colorless. Both compounds are soluble in water. When they are mixed, a double replacement chemical reaction occurs, in which the lead and potassium ions switch partners to form soluble potassium iodide KCl, and PbI2, which is a yellow solid that precipitates out of solution because it is insoluble in water.

Pb(NO3)2(aq)+2KI(aq)PbI2(s) + 2KNO3(aq)