Question

Define pH and pKa and explain how they are different.

Answer 1

pH is a measure of [H+´] ion concentration

and it is an equation which is modelled:

pH = -log([H+])

the scale is based on 10, that is, 1 to 2, implies a shigt in 10x amount

Also, the lower pH, the more acidic, since -log implies 10x more stronger.

pKa is similar to pH

pKa is the -log(Ka)

Ka = acid dissociation constant for any weak acid

Note that Ka is directly proportional to H+, therefore,the lower pKa, the more acidic

in a buffer we can relate both:

pH = pKa + log(A-/HA)

where A and HA are conjugate acid/base