In an exothermic reaction heat is evolved and system loses heat to the surrounding. For such system

In exothermic reaction heat energy is-

In isothermal process if heat is evolved from the system then

When no heat is absorbed by the system them from the surroundings, but work (w) is done on the system, the change in internal energy of the system is given as

What are the heat (q) sign conventions when heat is transferred from the surroundings to the system and that transferred from system to the surrounding?

If heat is evolved during a reaction, it is ____

A process in which the system does not exchange heat with the surroundings is known as