(20 pts) Thermal properties, [data from: Amorim et al. Journal of the Brazilian Society of Mechanical Sciences and Engineering (2023) 45:466] (a) The DSC curve of the same sample of PP as in Q2 is shown. The heating rate is 10C/min. (i) What transition is observed and what is the transition temperature? (ii) Is this an exothermic or endothermic reaction? Why do you say so? (iii) Crudely estimate the enthalpy change in this transition; use the correct sign in your answer. (b) The results from the dilatometry experiment of the same sample are shown. The slope of the linear region is calculated for you. (i) What is a? (ii) Explain in 1 sentence what happens to the curve above 160C. (iii) On the generic energy versus distance curve for molecular interactions shown below, explain what feature of this curve gives rise to an increase in the length of the sample as a function of temperature. (kcal/mol)