Question

In a test tube you add 2 mL of saturated chlorine water followed by about 1 mL of an organic solvent such as heptane (or cyclohexane). The test tube is shaken and you notice that the heptane layer has a yellow color. To this mixture you then add 1 mL of 0.1 M N a I. After shaking you notice a color change from yellow to purple in the heptane layer. What can you conclude about Cl2 and I minus from this experiment

Answer 1

The organic compounds (heptane/cyclohexane) will get dissolve in Cl₂ water forming a yellow colored solution.

When NaI is added into it, the following reaction between NaI and Cl2 takes place;

Cl₂ + NaI ⇒ I₂ + NaCl

In above reaction, oxidation state of Cl is getting reduced from 0 in Cl2 to -1 in NaCl.

Therefore, Cl2 is getting reduced and acting as an oxidizing agent in the reaction. While I⁻ is getting oxidised annd acting as a reducing agent