Heat of formation problem?

Question

When a 2.000 gram sample of pure phenol, C6H5OH(s), is completely burned according to the equation below, 65.98 kJ of heat is released.

C6H5OH(s) + 7 O2(g) → 6 CO2(g) + 3 H2O(l)

(b) Calculate the standard heat of formation, ΔH°f, of phenol in kilojoules per mole at 25°C.

knowing that
DHf of CO2 = -395.5
DHf of H2O (l) is -285.85


Thanks in advance,

Answer 1

1. Work out the Mr of phenol.
2. Work out the moles of phenol.
3. Calculate the molar enthalpy of combustion of phenol, remembering to put a - sign in front.
4. Write the equation for the formation of 1 mole of phenol from its elements.
5. Appreciate that you are actually given enthalpies of combustion of C and of H2 in the question.
6. Add up the correct molar multiples of the enthalpies of combustion of C and H2 as given in 4.
7. Subtract the molar enthalpy of combustion that you worked out in 3.

Answer 2

Sat, in his answer, used this term: "organic varieties" yet another term to look for, while describing a formation reaction, is this: "primary state" i might additionally upload that a formation reaction is written for one mole of product. So, as an occasion, this: 2H2(g) + O2(g) ---> 2H2O(l) isn't a formation reaction (even nonetheless all factors are of their primary states), via fact it leads to 2 moles of product.