Sodium Through Argon
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28. Why do phosphorus and sulfur form multiatomic P4 and S8 molecules, whereas nitrogen and oxygen in the second row form diatomic molecules? 29. Compare the oxyacids of P, S, and Cl with those of the second-row elements for coordination number and acidity. Why is phosphoric acid weaker than nitric acid? Which third-row oxyacid is more similar to nitric acid in strength? 30. Which third-row oxyacid is most like carbonic acid? In what ways? 31. What does "diagonality" of chemical properties mean when applied to the periodic table? Give examples involving metals, amphoterism, and oxyacid properties. 32. Why does the acidity increase among chlorine oxyacids in the series hypochlorous acid, chlorous acid, chloric acid, and perchloric acid? |
33. Why is HCl a stronger acid than HF, even though fluorine is
more electronegative than chlorine and presumably would pull the
bonding electron pair away from the proton more strongly? 34. Which is a stronger acid, H2S or H2O? Why? Which is stronger, H2S or HCl? Why? 35. When sodium metal reacts with chlorine gas, what is oxidized and what is reduced? 36. When a piece of metallic sodium is dropped into water, the first step of the reaction is one in which hydrogen gas is given off. In this step, which substance is oxidized and which is reduced? 37. The next and more dangerous consequence of dropping sodium in water is that the heat liberated ignites the hydrogen gas, which explodes. In this second step, what is oxidized and what is reduced? 38. In the reaction of hydrogen with oxygen, unlike that of sodium with chlorine, no ions are produced, and the sole product is covalently bonded water molecules. In what sense can one then say that oxidation and reduction have occurred? |
