Question

What is the white precipitate that forms at 100 degrees C?

A) Silver chloride
B) Barium sulfate
C) Lead iodide
D) Calcium carbonate

Answer 1

The white precipitate that forms at 100 degrees C is lead iodide (PbI2).

Step-by-step explanation:

The white precipitate that forms at 100 degrees C is lead iodide (PbI2). Lead iodide is a yellow precipitate that forms when solutions of lead (II) nitrate and potassium iodide are mixed. The reaction is as follows:

Pb(NO3)2 + 2KI → PbI2 + 2KNO3

When heated to 100 degrees C, the yellow lead iodide precipitate turns into a white precipitate due to the loss of water molecules.