If chlorine gas is bubbled through an aqueous solution of sodium iodide, the result is elemental iodine and aqueous sodium chloride solution. What kind of reaction took place?
single replacement
A chemical reaction
The reaction that took place is a redox reaction, specifically a single displacement reaction. This is because the chlorine gas (Cl₂) displaces the iodine (I) from the sodium iodide (NaI) solution, forming elemental iodine (I₂) and aqueous sodium chloride (NaCl). The balanced chemical equation for this reaction is:
Cl₂ + 2 NaI → I₂ + 2 NaCl
The reaction that took place in this case is a redox reaction known as a displacement reaction, specifically a single displacement reaction or a substitution reaction.
To understand why this reaction is a redox reaction, let's break down the process step by step:
1. Chlorine gas (Cl2) is bubbled through an aqueous solution of sodium iodide (NaI). The chlorine gas (Cl2) is highly electronegative and has a strong tendency to attract electrons.
2. In the solution, sodium iodide (NaI) dissociates into sodium ions (Na+) and iodide ions (I-). The chlorine gas (Cl2) molecules collide with the water molecules and break apart into chlorine ions (Cl-) and gain electrons.
3. The chlorine ions (Cl-) then take the place of iodide ions (I-) in the solution, as chlorine is more electronegative than iodine. This displacement reaction results in elemental iodine (I2) forming.
4. At the same time, the displaced iodide ions (I-) combine with sodium ions (Na+) to form sodium iodide (NaI) in the solution.
5. The result is elemental iodine (I2) and an aqueous solution of sodium chloride (NaCl). The sodium chloride is formed because the sodium ions (Na+) from the original sodium iodide combine with the chlorine ions (Cl-) that were freed during the reaction.
In this redox reaction, chlorine is reduced (gaining electrons) and iodine is oxidized (losing electrons). The chlorine gas acts as the oxidizing agent, while the iodide ions act as the reducing agent.
Overall, the reaction can be summarized as:
2NaI(aq) + Cl2(g) -> I2(s) + 2NaCl(aq)