For endothermic reaction ans. ΔH is negative ΔU is negative ΔH is positive ΔH = 0

For an endothermic reaction:

1. ΔH is positive: In an endothermic reaction, heat is absorbed from the surroundings into the system. This increases the enthalpy (H) of the system, so the change in enthalpy (ΔH) is positive.

2. ΔU is positive: The internal energy (U) of the system also increases in an endothermic reaction, as energy is absorbed from the surroundings. Therefore, the change in internal energy (ΔU) is positive.

3. ΔH is not negative: As mentioned above, ΔH is positive for an endothermic reaction because heat is absorbed from the surroundings.

4. ΔH is not equal to 0: In an endothermic reaction, there is a change in enthalpy as heat is absorbed from the surroundings. Therefore, ΔH is not equal to 0.