An experimenter attempts to carry out a single replacement reaction between solid iodine and a solution of potassium chloride.
Which is more reactive, iodine or chlorine?
Which of the following equations correctly predicts the products of the reaction?
i. [tex]I _2(s)+2 KCl _{( aq )} \rightarrow Cl _{2(g)}+2 KI _{( aq )}[/tex]
ii. [tex]I _2(s)+ KCl _{( aq )} \rightarrow KClI _2(s)[/tex]
iii. [tex]I _2(s)+2 KCl _{( aq )} \rightarrow 2 K_{( s )}+2 ClI _{( aq )}[/tex]
iv. [tex]I _2(s)+ KCl ( aq ) \rightarrow[/tex] no reaction
Answer (2)
Chlorine is more reactive than iodine.
Iodine cannot displace chlorine from potassium chloride.
Therefore, no reaction occurs.
The correct equation is: I 2 ( s ) + K Cl ( a q ) → no reaction. n ore a c t i o n
Explanation
Comparing Reactivity Iodine and chlorine are both halogens, and their reactivity decreases as you go down the group in the periodic table. This means that chlorine is more reactive than iodine.
Predicting the Reaction Outcome In a single replacement reaction, a more reactive halogen can displace a less reactive halogen from its salt. Since chlorine is more reactive than iodine, iodine cannot displace chlorine from potassium chloride (KCl). Therefore, no reaction will occur.
Identifying the Correct Equation The correct equation that predicts the products of the reaction is:
I 2 ( s ) + K Cl ( a q ) → no reaction
Final Answer Therefore, chlorine is more reactive than iodine, and the reaction between iodine and potassium chloride will not occur.
Examples
Single replacement reactions are commonly used in various industrial processes, such as extracting metals from their ores. For example, copper can be extracted from copper sulfate solution by reacting it with iron. The more reactive iron displaces copper from the solution, forming iron sulfate and solid copper. This principle is also applied in water purification, where chlorine is used to disinfect water by reacting with and neutralizing harmful bacteria and viruses.
Chlorine is more reactive than iodine, which means iodine cannot displace chlorine from potassium chloride. Therefore, the correct equation for the reaction is: I 2 ( s ) + K Cl ( a q ) → no reaction .
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