Question

I know what an Electrolyte and a non-electrolyte is, but how do I relate the number of particles in a given solution to the type of solute (electrolyte or non-electrolyte).

Answer 1

Generally number of particles present is calculated by knowing the number of moles.

0ne mole of substance contains Avagadro number of particles ie 6.023×10²³

For example one mole of Methane gas contains 6.023*10²³ Methane particles.

Number of moles is calculated by

Number of moles =

Electrolytes and Non-electrolytes:

Substances are classified into electrolytes and Non-electrolytes. The substance which can dissociates into its ions when dissolved in water is called as electrolyte and which cannot dissociates into its ions is called Non-electrolytes.

For example

Glucose is a non-electrolyte as it cannot dissociates into its ions.

Where as NaCl dissociates into sodium and chloride ions when dissolved in water. So it is an electrolyte.

Sodium chloride gives 2 ions on dissociation where as barium chloride gives 3 ions ( one barium ion and 2 chloride ions).

Number of particles present in a solution containing Non-electrolyte = Number of moles of the non-electrolyte * 6.023*10²³

Number of particles of non-electrolyte = Number of moles * 6.023×10²³

Number of particles present in a solution containing electrolyte = Number of ions electrolyte gives on dissociation* Number of moles of the non-electrolyte * 6.023*10²³

Number of particles of electrolyte = Number of ions formed * Number of moles * 6.023×10²³

For example number of particles present in a solution containing 5.85 g NaCl is

Number of moles of NaCl in 5.85 g of NaCl = 0.01 ( since moles = weight/molar mass)

Number of particles = 2 * 0.01 * 6.023 ×10²³

Actually number of particles should be 0.01*6.023×10²³

As number of particles appeared is twice that of calculated, we can say that the substance is electrolyte of AB type.

If number of particles observed and calculated are same, it is a non-electrolyte.