Chemistry Form 4: Chapter 7 - How to Differentiate Between Strong Acid and Weak Acid

A) Reaction between acids and reactive metals

• Strong acids can react with reactive metal faster and more vigorously. More hydrogen gas produced at a faster rate.
• Weak acids can react with reactive metal slower and less vigorously. Less hydrogen gas produced at a slower rate.

B) Electrical conductivity

 

Conductivity Behavior of Acids
Compounds	Appearance of light bulb	Classification Weak or Strong	Inference of Ions or Molecules
water, H2O	no light	weak	molecules
hydrochloric acid, HCl	bright	strong	ions
acetic acid, HC2H3O2	dim	weak	mostly molecules, less ions

• Strong acids able to conduct electricity better as shown in hydrochloric acid because it contains a large number of freely moving ions as strong acids dissociate completely in water.
• Weak acids conduct electricity weakly as shown in acetic acid because it contains a few number of moving ions as weak acids dissociate partially in water. Most of weak acids still remain in covalent molecule.