Miscellaneous II

What is the effect of raising the temperature on reaction rate? answerReaction rate increases (approximatelydoubles for each 10K increase).Note: the equilibrium position may shifteither in favor of products or reactants,depending on delta H (Le Chatelier's principle).	Why is hydrochloric acid (Ka » 1) a stronger acid than hydrofluoric acid (Ka = 3.5 x 10-4)? answerAn chlorine atom has a much larger radiusand more sheilding electrons than doesa fluorine atom and so the electrostaticforce of attraction on the bonding electronsis less. As a result, HCl dissociates morereadily than HF.
Why is phosphorous able to form such compounds as PF5 while nitrogen cannot? answerPhosphorous can make use of vacant d orbitalsto expand its valence orbitals.Nitrogen cannot.	Using the valence shell electron pair repulsion theory (VSEPR), what is the shape of PF5? answerThe electron pairs are oriented as far from each other as possible. Thus, the shape istrigonal bipyrimidal.