Answer:
. 1. This amino acid has a positively charged R group: ARGININE
2. This amino acid has a negatively charged R group: ASPARTATE
3. This amino acid has a neutral polar R group: NONE
4. This amino acid has a nonpolar aliphatic R: VALINE
5. This amino acid has an aromatic R group: TRYTOPHAN
Explanation:
1) Arginine contains an extra amino group bearing a positive charge, in its chain which imparts basic properties to it
2) Aspartate contains an extra carboxyl group with a dissociable protron. Once the Protron is dissociated, it carries an extra negative charge in its side chain (R)
3) NONE of the amino acids given belong to this group because amino acids with neutral polar R groups contain functional groups that form hydrogen bonds with water. But, this is not the case with tryptophan aspartate valine or arginine
4) Valine has a R group that is hydrocarbon in nature and thus hydrophobic.
5) Trytophan has a benzene ring in its side chain
Explanation:
It is known that at the equivalence point,
Equivalent of acid = equivalent of base ......... (A)
and, Equivalent = 
Therefore, equivalent of acid is calculated as follows.
Equivalent of acid = 
.......... (1)
Equivalent of base = 
............ (2)
Hence, using equation (A) we will calculate the concentration as follows.
M = 0.16 M
Thus, we can conclude that concentration of the unknown weak acid solution 0.16 M.
The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near itshydrogen atoms. When a neutral molecule has a positive area at one end and a negative area at the other, it is a polar molecule.
