I have learnt that internal energy U is a state function and

Last updated: 7/3/2023

I have learnt that internal energy U is a state function and it only depends on temperature So if Delta T 0 then Delta U 0 However when I was studying exothermic and endothermic reactions it was written in my textbook that at a constant temperature and pressure Delta U is negative for exothermic reactions How is that possible Shouldn t Delta U be zero since the temperature is constant