Question

The conversion of ozone into oxygen is exothermic, under what condition is ozone the most stable?
$2O_3\left(g\right)\rightleftharpoons 3O_2\left(g\right)$

• A. At low pressure and low temperature
• B. At high pressure and high temperature
• C. At high pressure and low temperature
• D. At low pressure and high temperature

Answer 1

The correct option is B At high pressure and high temperature

$2O_3\left(g\right)\rightleftharpoons 3O_2\left(g\right)$
If the above reaction occurs in a backward direction, then only the ozone becomes more stable.
The reaction is exothermic. So, high temperature favours backward reaction. Here, the number of moles of products is more than the number of moles of reactants. So, at high pressure the backward reaction favours. Hence, at high temperature and high pressure ozone is the most stable.