Question

Which is an example of a precipitation reaction?

A.
Solid C6H12O6 combines with O2 gas to produce CO2 gas and H2O gas.

B.
A solution of HCl mixes with a solution of NaOH to produce a solution of NaCl.

C.
A solution of AgNO3 mixes with a solution of NaCl to produce solid AgCl and a solution of NaNO3.

D.
Solid Fe combines with O2 gas to produce solid Fe2O3.

Answer 1

Answer;

C. A solution of AgNO3 mixes with a solution of NaCl to produce solid AgCl and a solution of NaNO3.

Explanation;

-Precipitation reactions occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate. Whether or not such a reaction occurs can be determined by using the solubility rules for common ionic solids.

-Precipitates are insoluble ionic solid products of a reaction, formed when certain cations and anions combine in an aqueous solution.

-A common example is that of the mixing of two clear solutions: silver nitrate (AgNO3) and sodium chloride (NaCl): The reaction is;

                          AgNO3 + NaCl = AgCl + NaNO3  

- The precipitate forms because the solid (AgCl) is insoluble in water. That is true for all precipitates - the solids are insoluble in aqueous solutions.