Acids and bases

[Bri MT]

Acids and Bases
According to the Bronsted Lowry model of acids and bases, an acid is any species which donates a hydrogen ion and a base is any species which accepts/receives a hydrogen ion. Since \(H^+\) has no electrons and 1 proton, sometimes people define acids as proton donors and bases as proton acceptors.

polyprotic acid: (‘many-proton acid’) donates multiple protons
monoprotic acid: (‘one-proton acid’) donates one proton.

Calculating pH & pOH
pH quantifies how acidic or basic an aqueous solution is; each increase by 1 pH represents a tenfold increase in the concentration of hydronium ions. The equation for pH is \(pH = -\log_{10}[H^+]\)This also means that \([H^+]\) = \(10^{-pH}\).
Remember, acidic -> more hydronium ions produced -> lower pH

We treat pOH similarly; ] \(pOH = -\log_{10}[OH^-]\) and \([OH^-]\) = \(10^{-pOH}\)

Calculating \(pK_{a}\) & \(pK_{b}\)
These values provide us with information about the strength of an acid (represented by the a) or base (represented by the b).
  \(pK_{a} = -\log_{10}[K_{a}]\) and  \(pKb = -\log_{10}[K_{b}]\)
\(K_{a}\) and \(K_{b}\)  are just calculated the same as any other equilibrium expression, and the a or b specifies that the reactant is an acid or base respectively.

Strong Acids:  more likely to act as an acid, considered to dissociate completely
-   Hydrochloric acid \(\ce{HCl}\)
-   Nitric acid \(\ce{HNO3}\)
-   Sulfuric acid \(\ce{H2SO4}\)
Weak Acids: likely to act as an acid, considered to dissociate incompletely
-   Carboxylic acids (e.g. \(\ce{C2H4O2}\) )
-   Carbonic acids \(\ce{H2CO3}\)
Strong Bases: more likely to act as a base, considered to dissociate completely
-   Group 1 hydroxides (e.g. \(\ce{NaOH}\) )
-   Barium hydroxide \(\ce{Ba(OH)2}\)
Weak Bases: likely to act as a base, considered to dissociate incompletely
-   Ammonia \(\ce{NH3}\)
-   Amines (e.g. \(\ce{C3H7NO}\))