# How do I calculate the standard enthalpy of formation for liquid ethanethiol? Do I use Hess's law? [closed]

Calculate a value for the standard enthalpy of formation for liquid ethanethiol, $\ce{C2H5SH}$. Use the equation given below and enthalpy of combustion data from the following table.

Just assume values and comment the methods to solve the problem, I'll try solving it.

Edit: I'm not sure whether you're supposed to use

$$\Delta H^\circ = \sum{\Delta H_f(\text{product})} - \sum{\Delta H_f(\text{reactant})}$$

because the given is enthalpy of combustion data, not heat of formation. I'm not quite sure what an enthalpy of combustion is.

• Not going to leave a full answer since there are piece I don't remember...generally for a hydrocarbon X, the enthalpy of combustion is the enthalpy of $\ce{X + O2 -> CO2 + H2O}$, suitably balanced. The problem is I don't recall what product you need on the right for sulfur-containing compounds...I think it might be $\ce{SO2}$, but I really have no clue. – chipbuster Jun 8 '17 at 2:54
• Welcome to Chem SE. It's good to see you trying to solve your own question. But please show it to us. Pinpoint where your stuck exactly. That can help us give you a specific and relevant answer. By the way, have a tour of this site. Visit the help center to learn how to ask and answer questions here. Good luck! – Pritt says Reinstate Monica Jun 8 '17 at 13:59
• Which table???Which equation??? Please consider adding the table and the equation (because knowing the substances whose heats of combustion are given is essential for solving this problem!) to your question. "Just assume values...", its like you are ordering us to solve your problem! – Archer Mar 10 '18 at 16:22