Why did we have you determine the reaction rate using reactant consumed per unit of time instead of product formed per unit of time?

Rate of reaction can be determined in terms of concentration of reactants consumed or concentration of product formed per unit time

Explanation: For the reaction below

A ===>B

The reactant is A while the product given is B.

Reaction rate = Δ[B]/Δt = -Δ[A]/Δt

The concentration of A will decrease with time while the concentration of B will increases with time.

The negative sign in -Δ[A]/Δt is to convert the expression to positive since the change will always be negative (decreases)

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.