Question

Which of the following observations and equations describe the displacement reactions of halide ions in aqueous solutions?

Option 1: When a solution of chlorine (Cl2) is added to a solution of sodium iodide (NaI), a brown coloration is observed, and the equation is 2NaI + Cl2 -> 2NaCl + I2.

Option 2: When a solution of silver nitrate (AgNO3) is added to a solution of potassium bromide (KBr), a white precipitate is formed, and the equation is AgNO3 + KBr -> AgBr(s) + KNO3.

Option 3: When a solution of potassium chloride (KCl) is added to a solution of silver nitrate (AgNO3), a white precipitate is formed, and the equation is KCl + AgNO3 -> KNO3 + AgCl(s).

Option 4: When a solution of sodium chloride (NaCl) is added to a solution of silver nitrate (AgNO3), a white precipitate is formed, and the equation is NaCl + AgNO3 -> NaNO3 + AgCl(s).

Answer 1

Displacement reactions of halide ions with silver nitrate in aqueous solutions result in the formation of precipitates. Options 2, 3, and 4 describe correct displacement reactions leading to the formation of silver bromide, silver chloride, and silver chloride precipitates respectively.

Step-by-step explanation:

The displacement reactions of halide ions in aqueous solutions involve the reaction of halide salts with silver nitrate to form a precipitate. These reactions are outlined below:

• When chlorine (Cl2) is added to sodium iodide (NaI), a brown coloration is observed, corresponding to the formation of iodine (I2), which means that the equation 2NaI + Cl2 -> 2NaCl + I2 does indeed describe a displacement reaction where chlorine displaces iodide ions.
• When silver nitrate (AgNO3) solution is added to various solutions of halide salts like potassium bromide (KBr), potassium chloride (KCl), or sodium chloride (NaCl), a precipitation reaction occurs. Silver chloride (AgCl) is a white precipitate, silver bromide (AgBr) is cream-colored, and silver iodide (AgI) is yellow.

In summary, the reactions provided as Option 2, Option 3, and Option 4 all correctly describe the displacement reactions, producing precipitates of AgBr, AgCl, and AgCl respectively, with their corresponding soluble nitrates remaining in solution.