Consider a reaction that has a positive δh and a positive δs. which of the following statements is true? a) this reaction will be spontaneous only at high temperatures. b) this reaction will be spontaneous at all temperatures. c) this reaction will be nonspontaneous at all temperatures. d) this reaction will be nonspontaneous only at high temperatures. e) it is not possible to determine without more information.

A) This reaction will be spontaneous only at high temperatures

Explanation:

= +ve, reaction is non spontaneous

= -ve, reaction is spontaneous

= 0, reaction is in equilibrium

Using Gibbs Helmholtz equation:

Given :

Thus the value of    is negative and spontaneous when temperature is high.

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.