thermochemical equation

Question 1

what are the conditions of a thermochemical equation?

Answer 1

1- it must be balanced
2- the physical state of the reactants and products must be written
3- there should be a positive or negative sign before the delta H
4- when multiplying or dividing the coefficients of the two sides of the equation with certain numerical coefficients the same must be applied to delta H
5- when the process is inversed the sign of delta H must be inversed

Question 2

give reason: we can write the coefficients of the balanced equation as fractions?

Answer 2

because the coefficients represents the number of moles of the reactants and the products not the number of moles or atoms

Question 3

give reason: we must write the physical state of the reactants and products in a thermochemical equation?

Answer 3

because heat content changes with the change of the physical state of the substance

Question 4

what is the bond energy?

Answer 4

it is the amount of energy absorbed to break the bonds or released during the formation of bonds in one mole of the substance