Question

Imagine you are a professor and want your students to perform a precipitation reaction. They will collect the precipitate and weigh it. At the end of the experiment, all materials must be disposed of correctly and safely. The procedure in the textbook calls for mixing silver nitrate with sodium chloride. The safety warning alerts you that silver salts are toxic, particularly to aquatic life.

1a. Write a balanced chemical equation for the reaction that would occur between silver nitrate with sodium
chloride. Include all physical states.

1b. What compound forms the precipitate?

1c. How might you make this experiment more "green"? What principle of the green chemistry was employed in making this change?

1d. Write a precipitation reaction for which the products are less hazardous than the textbook procedure.

1e Assuming a 100% yield, how many grams of each starting materials is needed to make 2.00 g of the precipitate in your reaction?

Answer 1

1a) Balanced Chemical equation is AgNO₃(aq) + NaCl(ag) = AgCl(s) + NaNO₃(aq)

1b) AgCl forms the precipitate

1c) We might use HCl instead of NaCl. thus it will form HNO₃ in solution which is used in this precipitation reaction.

The Waste prevention principle of green chemistry is used here. Where no extra product is formed as waste.

1d)   AgNO₃(aq) + HCl(aq) = AgCl(s) + HNO₃(aq)