Now, in an exothermic, the opposite holds. In an exothermic reaction, the bonds formed are stronger than the bonds broken. Therefore, the final solution will hold its molecules very tightly and will not let them go. They will not be able to escape, will be less likely to go into the gas state. And that's why less gas molecules will be present in the space above and the deeper pressure will be lower. And that's why in each situation they're curved downward.