Question

How do you determine the sign of (delta) s and (delta ) h?

Answer 1

hints about enthalpy (delta H) and entropy (delta S):

Enthalpy is the heat of reaction. A positive value means that the surroundings are doing work on the system, and a negative value means the opposite, that the system is doing work on the surroundings. So if we're turning gaseous water into oxygen and hydrogen gas, would that release energy and have a negative delta H or require an overall input of energy and have a positive delta H?

For entropy, delta S is basically a measure of the change in order/disorder of the reaction. Increasing order gives us a negative delta S value, and decreasing order gives a positive delta S value. Easy ways to detect a change in entropy are phase changes (a solid has less entropy than a liquid, which has less entropy than a gas) and an overall change in moles of gas from reactants to products (an increase in moles of gas would indicate disorder over a wider area, which is an increase in entropy)