Question

$Cl+Cl\to C{l}_2$, this is an example for __________.

• A. Endothermic reaction
• B. Exothermic reaction
• C. Either exothermic or endothermic
• D. Neither exothermic nor endothermic

Answer 1

Answer: (B)

Exothermic reaction

$C{l}^{\cdot }+C{l}^{\cdot }⟶Cl:Cl$

As two Chlorine atoms come together their electrostatic energy decreases. According to the law of conservation of energy, this energy will be transformed into heat energy.
So, $Cl+Cl⟶C{l}_2$ is exothermic reaction.