Question

Give one example of a substance which contains:

(c) both ions and molecules.

Answer 1

Electrolytes

• Electrolytes are those ionic compounds that allow the conduction of electricity, either in their aqueous solutions or in molten states.
• Electrolytes can be strong or weak.

Strong and weak Electrolytes

• Strong electrolytes dissociate completely whereas weak electrolytes do not dissociates completely.
• The weak electrolytes contain both ions and molecules.
• For example, acetic acid $\left({\text{CH}}_{\text{3}}\text{COOH}\right)$
• Its partial dissociation is depicted as follows:
• ${\text{CH}}_{\text{3}}\text{COOH}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right){\text{⇌CH}}_{\text{3}}{\text{COO}}^{-}\left(\mathrm{aq}\right)\text{+}{\mathrm{H}}_3{\mathrm{O}}^{+}\left(\mathrm{aq}\right)$
• The undissociated acetic acid acts as a molecule while the dissociated species acts as ions, that is acetate ions and hydronium ions.