Under what conditions can a non-spontaneous reaction be made spontaneous? a. when an endothermic reaction has a positive change in entropy and the temperature is greatly increased b. when an endothermic reaction has a positive change in entropy and the temperature is greatly decreased c. when an exothermic reaction has a positive change in entropy and the temperature is greatly increased d. when an exothermic reaction has a positive change in entropy and the temperature is greatly decreased e. when an exothermic reaction has a negative change in entropy and the temperature is greatly increased to if you know the correct answer.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."