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       #Post#: 647--------------------------------------------------
        Chemistry Questions
   DIR By: helpthisguy
       Date: September 11, 2012, 4:51 pm
       ---------------------------------------------------------
       not sure if my post came up or anything but here it is again
       sorry bout that guys
       An uncharged molecule has:
       A.  Hydrogen bonds
       B.  lots of oxygen
       C.  several ionic bonds
       D.  a high degree of polarity (my answer )
       E.  none of the above
       If an element has 7 electrons in its valence shell, it is
       likely to:
       A.  be a noble gas
       B.  make H bonds
       C.  make covalent bonds
       D.  make ionic bonds (my answer )
       If a solution goes from pH 3 to pH 5, the acidity of the
       solution has:
       A.  increased by a factor of 2
       B.  increased by a factor of 20 (my answer )
       C.  increased by a factor of 100
       D.  decreased by a factor of 2
       E.  decreased by a factor of 100
       Water is polar because:
       A.  The hydrogen nuclei in a water molecule have partial
       positive charge. (my answer )
       B.  The oxygen nucleus has a partial positive charge
       C.  The hydrogen nuclei have a +1 charge
       D.  The oxygen nuceli have a -1 charge
       Which of the following molecules is composed of monomer units
       containing a sugar, a phosphate group, and a nitrogen-containing
       base?
       A.  nucleic acid (my answer )
       B.  polysaccharide
       C.  phospholipid
       D.  protein
       When a protein such as keratin is treated with a chemical that
       disrupts disulfide (-S-S-) bonds, which level of protein
       structure will be affected?
       A.  primary (1) structure of the protein
       B.  secondary (2) structure of the protein
       C.  tertiary (3) structure of the protein (my answer)
       D.  all of the above
       #Post#: 648--------------------------------------------------
       Re: Re: Chemistry Help
   DIR By: helpthisguy
       Date: September 11, 2012, 5:47 pm
       ---------------------------------------------------------
       An uncharged molecule has:
       A.  Hydrogen bonds
       B.  lots of oxygen
       C.  several ionic bonds
       D.  a high degree of polarity (my answer )
       E.  none of the above
       If an element has 7 electrons in its valence shell, it is
       likely to:
       A.  be a noble gas
       B.  make H bonds
       C.  make covalent bonds
       D.  make ionic bonds (my answer )
       If a solution goes from pH 3 to pH 5, the acidity of the
       solution has:
       A.  increased by a factor of 2
       B.  increased by a factor of 20 (my answer )
       C.  increased by a factor of 100
       D.  decreased by a factor of 2
       E.  decreased by a factor of 100
       Water is polar because:
       A.  The hydrogen nuclei in a water molecule have partial
       positive charge. (my answer )
       B.  The oxygen nucleus has a partial positive charge
       C.  The hydrogen nuclei have a +1 charge
       D.  The oxygen nuceli have a -1 charge
       Which of the following molecules is composed of monomer units
       containing a sugar, a phosphate group, and a nitrogen-containing
       base?
       A.  nucleic acid (my answer )
       B.  polysaccharide
       C.  phospholipid
       D.  protein
       When a protein such as keratin is treated with a chemical that
       disrupts disulfide (-S-S-) bonds, which level of protein
       structure will be affected?
       A.  primary (1 degree) structure of the protein
       B.  secondary (2 degree) structure of the protein
       C.  tertiary (3 degree) structure of the protein (my answer)
       D.  all of the above
       #Post#: 649--------------------------------------------------
       Re:  Chemistry Questions
   DIR By: Michel
       Date: September 12, 2012, 4:37 am
       ---------------------------------------------------------
       Your 1st Question is quite ambigous. An uncharged molecule could
       have a high degree of polarity. That would mean a partial
       positive charge at one end, and a partial negative charge at the
       other end. Option E sounds good also. I do not know what is
       meant by lots of oxygen. N2O5 has 'lots of oxygen' and It is
       uncharged.
       you are correct in the 2nd question.
       The third question:
       pH = -logH3O+
       at pH=3
       -logH3O+ = 3
       [H3O+] = 10^ -3
       at pH=5
       -logH3O+ = 5
       [H3O+] = 10^ -5
       Find the ratio between the [H3O+] concentrations to obtain your
       answer
       4th question, correct.
       5th question: The tertiary structure of the protein will be
       affected. The S-S bonds determine the coiling shape of the
       keratin molecule which is the tertiary structure
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