Question

Are halogens reactive with water?

Answer 1

1. Yes, halogens are reactive with water. Fluorine ($\mathrm{F}$), Chlorine ($\mathrm{Cl}$), Bromine ($\mathrm{Br}$) and Iodine ($\mathrm{I}$) are the elements of the halogen family.
2. They belong to the ${17}^{th}$ group in the periodic table on the right-hand side.
3. Their reactivity decreases as we move down the group.
4. Chlorine reacts with water to form Hydrochloric acid ($\mathrm{HCl}$) and Hypochlorous acid ($\mathrm{HClO}$). The reaction is given below-

$$\begin{gathered} {\mathrm{Cl}}_2+{\mathrm{H}}_2\mathrm{O}\to \mathrm{HCl}+\mathrm{HClO} \\ \left(\mathrm{Chlorine}\right)\left(\mathrm{Water}\right)\left(\mathrm{Hydrochloric}\mathrm{acid}\right)\left(\mathrm{Hypochlorous}\mathrm{acid}\right) \end{gathered}$$

5. Bromine reacts in the same way to form Hydrobromic acid ($\mathrm{HBr}$) and Hypobromous acid ($\mathrm{HBrO}$).

6. Iodine reacts with water to form Hydroiodic acid ($\mathrm{HI}$) and Hypoiodous acid ($\mathrm{HIO}$). But the reaction is slower as the reactivity of halogens decreases as we move down the group. The following reaction takes place-

$$\begin{gathered} {\mathrm{I}}_2+{\mathrm{H}}_2\mathrm{O}\to \mathrm{HI}+\mathrm{HIO} \\ \left(\mathrm{Iodine}\right)\left(\mathrm{Water}\right)(\mathrm{Hydroiodide}\mathrm{acid})\left(\mathrm{Hypoiodous}\mathrm{acid}\right) \end{gathered}$$

7. Fluorine reacts explosively with water forming Hydrogen fluoride ($\mathrm{HF}$) and Oxygen ( ${\mathrm{O}}_2$). Since Fluorine has the highest reactivity among all halogens as it is placed on the top of the group and is smaller in size with the highest electronegativity among halogens. The reaction is given below-

$$\begin{gathered} 2{\mathrm{F}}_2+{\mathrm{H}}_2\mathrm{O}\to 4\mathrm{HF}+{\mathrm{O}}_2 \\ \left(\mathrm{Fluorine}\right)\left(\mathrm{Water}\right)(\mathrm{Hydrogen}\mathrm{Fluoride})\left(\mathrm{Oxygen}\right) \end{gathered}$$