Question

What is meant by strong bases and weak bases? Classify the following into strong bases and weak bases:
NH₄OH, Ca(OH)₂, NaOH, KOH, Mg(OH)₂

Answer 1

 Strong bases ionise completely in water, producing huge amounts of hydroxide ions (OH⁻ ions). Generally, basic or alkali solutions of pH 8, 9 and 10 are considered weak bases or alkalis.

Weak bases ionise partially in water, producing less amounts of hydroxide ions (OH⁻ ions). 
Basic or alkali solutions of pH 11,12,13 and 14 are considered strong bases or alkalis.

Let us classify the given bases as strong or weak.
 

Strong bases	Weak bases
Sodium hydroxide, NaOH Potassium hydroxide, KOH	Ammonium hydroxide, NH4OH Calcium hydroxide, Ca(OH)2 Magnesium hydroxide, Mg(OH)2