How do acids and bases differ?

1 Answer
Jun 16, 2018

Answer:

Given a specific solvent.....

Explanation:

...the ACID is the characteristic cation of the solvent, and any acidic substance added to it will cause an increase in the concentration of this cation. And a base is the characteristic anion of the solvent, and any basic substance added to it will cause an increase in the concentration of this anion.

Water is a solvent for which this equilibrium is well-quantified, and under standard conditions....

#2H_2O(l)rightleftharpoonsH_3O^+ + HO^-#

Where #K_"autoprotolysis"=[H_3O^+][HO^-]=10^-14#

And of course, we can take #log_10# of both sides of this expression to give....

#log_10{[H_3O^+][HO^-]}=underbrace(log_(10)10^-14)_"= -14 by definition of the log function"#

And so we get....

#underbrace(-log_10[H_3O^+])_"pH"underbrace(-log_10[HO^-])_"pOH"=14#

And at last an expression you will use habitually...

#pH+pOH=14#

And so given an aqueous solution that is highly acidic, #pOH# tends high....#pH# tends low to negative...and in a base solution vice versa. Got all that?