Question

Hydrogen combines with chlorine in the——— (presence/absence) of sunlight.

Answer 1

• The reactions that is occurring in the presence of sunlight are called photochemical reactions.
• Hydrogen reacts with chlorine violently in the presence of sunlight to form Hydrogen chloride.
• $\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{sunlight}}{\to }\underset{\mathrm{Hydrogen}\mathrm{chloride}}{2\mathrm{HCl}\left(\mathrm{g}\right)}$

Hence, hydrogen combines with chlorine in the presence of sunlight.