delta h and u

[Maryam Alturki]

Hi can someone give me a clear explanation of what delta h and delta u are and how we use them in the equations? so confused idk what they're even for

[Emily Lee 2H]

Delta H is the heat energy that flows into a system which will have a positive value or out of a system which will have a negative value. The equation is deltaH=Mc(deltaT)
Delta U is the total change in internal energy of a system. The equation is deltaU=W+H

[Jocelyn Ni 3C]

Enthalpy change, ΔH, is the amount of heat released or absorbed by the system in a reaction. Δ H = mcΔT
ΔU is the total change of internal energy in a system. ΔU = q + w where q is energy transferred by heating and w is the energy transferred by compression
ΔH and ΔU can sometimes be linked together. When pressure is constant, ΔU = qp + w. qp just means q under constant pressure. We know that qp = ΔH and w = -PΔV. So this gives us ΔU = ΔH - PΔV.
If both pressure and volume are constant, then ΔU = ΔH. there is no work being done by expansion.

[405995505]

The difference between the two is that delta H is simply the energy used in the form of heat. However, delta U, is specifically the systems internal energy. Therefore, delta U tends to be used for things such as closed systems.

[405995505]

The difference between the two is that delta H is simply the energy used in the form of heat. However, delta U, is specifically the systems internal energy. Therefore, delta U tends to be used for things such as closed systems.