Question

During chemistry, Dan mixes two clear, colorless solution and mixing them produces a yellow precipitate in a clear, colorless final solution as shown by the chemical equation.

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

What physical evidence indicates that there has been a chemical reaction?

Answer 1

Answer: Formation of precipitate indicates that there has been a chemical reaction.

Step-by-step explanation:

Chemical reaction: It is defined as change in arrangement of the atoms so as to form a new substance.

Mixing of two clear solutions that is lead nitrate and potassium iodide gives out yellow solid precipitate of lead iodide with aqueous solution of potassium nitrate.

`Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)`

The physical evidence which indicates that chemical reaction has been taken place is formation of yellow solid precipitate of lead iodide ,(
`PbI_2`).