what happens in a chemical reaction?  what does activation energy (EA) mean?

uce the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction observations conclusions The reverse of this reaction is always spontaneous but proceeds slower at temperatures below 132. °C. AH is (pick one) AS is (pick one) His (pick one) B This reaction is endothermic. AS is (pick one) This reaction is spontaneous except below 110. °C but proceeds at a slower rate below 135. °C. AH IS (pick one) AS is (pick one)v

Briefly discuss each of the three reaction types we learned. What are their differences? Similarities?What condition must be met for a reaction to take place? Hydration: Hydrogenation: Dehydration:

NaCl (s) -> NaCI (aq) is accompanied by an increase in entropy because [Select] [Select] a solute was dissolved in water, forming a solution the number of products is greater than the number of reactants the phase change from vaporization is towards a higher internal energy