The net potential energy en between two adjacent ions is sometimes represented by the expression: en = -(c/r) + d exp(-r/p)
in which r is the interionic separation and c, d, and p are constants whose values depend on the specific material.
(a) derive an expression for the bounding energy eo in terms of the equilibrium interionic separation ro and the constants d, and p using the following procedure:
1. differentiate en with the respect to r and set the resulting expression equal to zero.
2. solve for c in terms of d, p, and ro.
3. determine the expression for eo by substitution for c in the equation en = -(c/r) + d exp(-r/p)
(b) derive another expression for eo in terms of ro, c, and p usin

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o