Question

The pair of compounds that can exist together is

• A. $FeCl_3,SnCl_2 $
• B. $HgCl_2,SnCl_2$
• C. $FeCl_2,SnCl_2$
• D. $FeCl_3,Kl $

Answer 1

The Correct Option is C

 The question asks us to determine which pair of compounds can coexist without reacting with each other adversely. To solve this, let's examine the chemistry of each compound, particularly considering their oxidation states and potential for redox reactions.

1. \(FeCl_3\) with \(SnCl_2\)
   • \(FeCl_3\) is iron(III) chloride, where iron is in the +3 oxidation state.
   • \(SnCl_2\) is tin(II) chloride, where tin is in the +2 oxidation state.
   • If these two compounds are present together, \(SnCl_2\) can potentially reduce \(FeCl_3\) to \(FeCl_2\), while itself being oxidized to \(SnCl_4\). Thus, these cannot coexist without reaction.
2. \(HgCl_2\) with \(SnCl_2\)
   • \(HgCl_2\) is mercury(II) chloride, where mercury is in the +2 oxidation state.
   • \(SnCl_2\) (tin in +2 state) can reduce \(HgCl_2\) to metallic mercury, so these cannot coexist stably.
3. \(FeCl_2\) with \(SnCl_2\)
   • \(FeCl_2\) is iron(II) chloride, where iron is in the +2 oxidation state.
   • Both \(FeCl_2\) and \(SnCl_2\) are in the +2 oxidation state, and there is no tendency for redox reactions between them. Therefore, they can coexist without reacting.
4. \(FeCl_3\) with \(KI\)
   • In this pair, \(KI\) can reduce \(FeCl_3\) to \(FeCl_2\), while itself being oxidized to iodine. Hence, these cannot coexist without reaction.

Based on the analysis above, the pair of compounds that can exist together without undergoing any chemical reaction is \(FeCl_2\) and \(SnCl_2\). They are chemically stable when coexisting because they do not engage in redox reactions with each other. Therefore, the correct answer is:

\(FeCl_2, SnCl_2\)