
As long as the equation in question can be expressed as the sum of the three equations with known enthalpy change, its
can be determined with the Hess's Law. The key is to find the appropriate coefficient for each of the given equations.
Let the three equations with
given be denoted as (1), (2), (3), and the last equation (4). Let
,
, and
be letters such that
. This relationship shall hold for all chemicals involved.
There are three unknowns; it would thus take at least three equations to find their values. Species present on both sides of the equation would cancel out. Thus, let coefficients on the reactant side be positive and those on the product side be negative, such that duplicates would cancel out arithmetically. For instance,
shall resemble the number of
left on the product side when the second equation is directly added to the third. Similarly
Thus
and

Verify this conclusion against a fourth species involved-
for instance. Nitrogen isn't present in the net equation. The sum of its coefficient shall, therefore, be zero.

Apply the Hess's Law based on the coefficients to find the enthalpy change of the last equation.

The gibbs free energy of the reaction of diamond to graphite is equal to -2.90 kJ/mol. The free energy is negative which means that the reaction is spontaneous. Therefore, the forward reaction is favored. Hope this helps. Have a nice day.
Answer:
Pure compounds include elements and compounds where a combination of two or more pure substances is a mixture. Only one type of atom comes in the form of a pure element. Multiple atoms consist of a molecule and different atoms consist of a compound. These are all pure substances and individually.
Answer:
978.19° C
Explanation:
P1V1/T1 =P2V2/T2 Since the pressure is constant, this can be written as
V1/T1 = V2/T2 RE-ARRANGE TO
V2 * T1/V1 = T2 Note: T must be in Kelvin!!
1.5 L * (273.15 + 23) / (.355 L ) = T2 = 1251.338 K =978.19 C