The standard reaction free energy is the total energy change of a chemical reaction that occurs at standard conditions. The standard reaction free energy is calculated by subtracting the heat of formation from the enthalpy of formation.
standard reaction free energy = -Hf-Hf
The standard Gibbs free energy, on the other hand, is the total of the enthalpy and the entropy. The Gibbs free energy is a thermodynamic potential that depends on the enthalpy and entropy of a system. The change in the Gibbs free energy is equal to ΔG=ΔH-TΔS.
The enthalpy of formation is a measure of how much heat must be put in to break down a compound into its constituent elements. The heat of formation is an estimate of how much heat will be released when the same compound is formed from its constituent elements.
<h3>How is the standard reaction free energy calculated?</h3>The standard reaction free energy is the change in Gibbs free energy, which is the enthalpy minus the entropy. This can be calculated by using E=ΔH-TΔS. The ΔG for a reaction with a standard state change from
atm to
K (the most common atmospheric pressure and temperature), and 1 mol of reactants is equal to 0. The ΔG
for a reaction with standard state changes from 1 atm to 298 K and from
to
atm are equal to
.
The standard reaction free energy can be calculated by using the following equation:
E=ΔH-TΔS, where E is the standard free energy of the reaction.
To learn more about standard reaction free energy, visit:
SPJ4
Answer:
minimum length of a surface crack is 18.3 mm
Explanation:
Given data
plane strain fracture toughness K = 82.4 MPa m1/2
stress σ = 345 MPa
Y = 1
to find out
the minimum length of a surface crack
solution
we will calculate length by this formula
length = 1/π ( K / σ Y)²
put all value
length = 1/π ( K / σ Y)²
length = 1/π ( 82.4 / 345× 1)²
length = 18.3 mm
minimum length of a surface crack is 18.3 mm