Standard Reaction Enthalpy Lecture Example

[Jack Amos 2I]

In lecture, Dr. Lavelle displayed the reaction with graphite (the most stable form of C) and gaseous H2 & O2, forming ethanol. The standard reaction enthalpy ended up being (delta)H°= -555.38 kJ. How did we end up computing this value? Was it a given value? If all the reactants were in their most stable form when calculating the (delta)H° of the reaction, would the standard enthalpy of formation for each reactant be zero?

[905783577]

The value was given. Also, it would not be zero because even in its most stable form, only lone elements have a standard enthalpy of formation of zero.

[Gianna Sciole 2F]

the value of the standard reaction enthalpy was given. this is a value that if we did the problem, we would be given in the question. it wouldn't be zero because ethanol is not a single element and instead is a compound.