Electrophiles are reagents attracted to electrons.
Electrophiles tend to be electron-deficient and carry partial positive charges. They are attracted to species with lone pairs of electrons. For example, protons 
have no electrons and tend to share ones with other species, hence behaving as electrophiles in aqueous reactions. In the reaction between 
and ammonia 
, protons would be attracted to lone electron pairs on nitrogen atoms in ammonia molecules, which carry partial positive charges.
The Lewis Acid-base theory define Acids as species that accept electron pairs in a particular acid-base reaction. Electrophiles, by definition, tend to accept electrons. Lewis acids thus behaves as electrophiles in acid-base reactions. In the previous example, demonstrates acidic behavior and can be inferred as an electrophile.
Two oxygen atoms in a oxygen molecule share two electrons<span>. Oxygen atoms only have 6 </span>valence electrons<span> (</span>electrons<span> in the outer shell). They want 8 </span>electrons<span> so they need to steal two or share two.</span>
You have to use the Henderson-Hasselbalch equation. Keep in mind that because the Pka is given the equation changes form slightly:
PH = Pka + log[acid/base]
Step 1 (Figure out the concentrations):
0.282 M of Acid (C6H5OOH) - 0.150 M = 0.132 M of acid
0.282 M of Base (C6HCOO) + 0.150 M = 0.432 M of bas3
Step 2 (Plug into equation):
PH = Pka + log[acid/base]
PH = 4.20 + log[0.132 M/0.432 M]
PH = 3.69
The pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.
