Which reaction produces an insoluble product? A
2KI + Pb(NO )2 → → PbI, + 2KNO
B
2AgNO3 + Ca(CH,02)2 + Ca(NO3)2 + 2AgC, H,O,
C
3BaCl2 + ALLS
→ 2AlCl3 + 3BaS
.
D
SrBr, + Mg(OH)2 → MgBr, + Sr(OH)2

The correct option is A).

Explanation:

Precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.

For the given chemical reactions:

A):

The iodide of lead is generally insoluble in water. Thus, lead iodide is a precipitate.

B):

The nitrates and acetates of all metals are soluble in water.

C):

The sulfide of barium is soluble in water.

D):

The hydroxide of strontium is soluble in water.

Hence, the correct option is A).

"the periodic table is arranged in order of atomic number."

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.