Tutor profile: Corey P.
Subject: Organic Chemistry
Rank the following in terms of Nucleophilicity: OH-, H2O, NH2-, ignoring any solvent effects.
NH2-, OH-, H2O. Nucleophilicity is effected by a number of factors, in this case the charge and electronegativity are the two main factors. Compounds with negative charges are better nucleophiles, as they contain more elctron density, therefore H2O is the least nuecleophilic. As nuecleophiles donate a lone pair, a more electronegative atom is less likely to donate electrons, therefore the less electronegative atom (N) will be more nucleophilic than the less electronegative atom (O), if charge and steric factors are similar. Thus, NH2- is more nucleophilic than OH-.
What does the enzyeme malate dehydrogenase do?
Based on the name of the enzyeme, it converts the substrate "malate" into a product (in this case oxaloacetate). Furthermore "dehydrogenase" removes hydrogen atom(s) from the substrate.
Subject: Basic Chemistry
List multiple atoms that would be isoelectronic to neon.
Neon is a noble gas, and will thus have a full shell of electrons. For an atom to be isoelectronic with another, they must have the same number and structure of valence electrons. Two immediate answers would be F- and Na+, as F has gained an electron and Na has lost one, thus giving them the same number and structure of electrons as neon. In general, any atom (1) that gains X number of electrons will be isoelectric to an atom (2) that is X groups to the right of atom 1 (F for example). The reverse is true for atoms that lose electrons, as they will be isolectric to atoms X groups to the left of atom 1 (Na for example). Therefore a more complete list would include O-2, N-3, Mg+2, and so on.
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