Question

What is the difference between Sodium Hydroxide and Potassium Hydroxide?

Answer 1

Sodium and potassium are two different elements in the periodic table. They both form hydroxides which are alkaline in nature. From this itself we can find out an elementary difference between the both. $NaOH$ is the chemical formula for Sodium hydroxide and $KOH$ is the chemical formula for Potassium hydroxide.

Complete answer:

| Sodium Hydroxide| Potassium Hydroxide
---|---|---
Chemical formula| $NaOH$ is the chemical formula| $KOH$ is the chemical formula
Commonly known as| Commonly known as lye or caustic soda| Commonly known as Potash
Atomic weight| Atomic weight is $39.997\;{\text{ }}g/mol$| Atomic weight is $56.1056\;{\text{ }}g/mol$
Number of protons in the metal| $Na$ has 11 protons | $K$ has 19 protons
Reaction with water| Reaction with water is highly exothermic| Reaction with water is slightly less exothermic
Stains| $NaOH$ leaves a yellow stain| $KOH$ solutions leave a translucent stain that is colourless
Solubility | Less soluble in water, methanol and ethanol| More soluble in water, methanol and ethanol
Uses| It is used in drain cleansers and in paper manufacturing industry in high quantities| It is used in the manufacture of certain fertilisers and soap.
Conductivity | Less conductive| More conductive.

Note:
While choosing either of these we have got the best in both of them. You will be having a lowering in price if we use Potassium Hydroxide alone. But you will get a faster penetration and better rinsing product than if you use Sodium Hydroxide.
There are also a lot of similarities in both of them.
Both can be used in the soap manufacturing industry as a base. $NaOH$ will give you solid opaque bar soaps whereas $KOH$ will give translucent clear liquid soaps.