The cavities in teeth is often filled with alloy of metals to avoid bacterial infections. However, when a person with dental filling ehew an active metal like aluminium foil acceidently, he experiences severe pain in teeth. The pain is due to a spontaneous discharge of a galvanic cell reaction which is set inside the mouth of person. The active metal serve as anode and dental filling act as inert electrode on which reduction of `O_(2)` gas takes place.
`E_(Al^(3+)|Al)^(@)=-1.66` volt: `E_(O_(2),H^(+)|H_(2)O)^(@)=+1.23` volt
What is the net cell reaction assuming acidic conditions in the mouth?
A. `4Al(s)+3O_(2)(g)+6H_(2)Orarr4Al(OH)_(3)(s)`
B. `4Al(s)+2O_(2)(g)+8H^(+)(aq)rarr4Al^(3+)+4H_(2O`
C. `4Al(s)+3O_(2)(g)+12H^(+)(aq)rarr4Al^(3+)(aq)+6H_(2)O`
D. `4Al(s)+3O_(2)(g)rarr2Al_(2)O_(3)(s)`
