Strong acids and strong bases represent strong electrolytes that completely dissociate in water, while weak acids and bases represent weak electrolytes with only partial dissociations in water.
Take a look at my 4-minute video on how to identify acids, bases and their varying strength based on the periodic table (no mnemonics needed!):
Based on previous concepts, we can view an acid or base in three ways.
1) Under the Bronsted-Lowry definition, an acid donates a proton (H+) ion, while a base accepts a (H+) ion.
2) Under the Arrhenius definition, an acid increases the hydrogen ion or hydronium ion (H3O+ or H+) concentration when dissolved in aqueous solutions, while a base increases hydroxide ion (OH–) concentration.
3) Under the Lewis definition, an acid accepts an electron pair, while a base donates an electron pair.
On the typical pH scale an acid will fall below a pH of 7, while a base will fall above a pH of 7.
Strong Acids & Strong Bases
Strong acids are classified as strong electrolytes that have complete dissociation in water.
Strong Acid Dissociation Equation
Like strong acids, strong bases also represent strong electrolytes that are completely soluble into ions.
Strong Base Dissociation Equation
The most commonly discussed 7 strong acid examples include: HCl, HBr, HI, HNO3, HClO3, HClO4 and H2SO4.
The most commonly discussed strong base examples include: LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2 , Sr(OH)2 and Ba(OH)2.
Weak Acids & Weak Bases
Both weak acids and weak bases are classified as weak electrolytes that have partial dissociation in water.
Weak Acid Dissociation Equation
Weak bases share similar characteristics to weak acids in that they are also weak electrolytes that only partially dissociate.
Weak Base Dissociation Equation
Based on these dissociation patterns you can say that weak acids and bases represent poor conductors, while strong acids and bases represent good conductors and good electrolytes.
Beyond Identification and Classification
After identifying and classifying acids (HA) and bases (A–) you will move onto calculating pH (-logH+) and pOH (-logOH–) from their concentrated and dilute solutions.
The calculating of pH and pOH of acids, bases and their salts will be based on acid strength or base strength determined from their Ka, Kb, pKa or pKb.