Question

What is ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ and find its n-factor in a basic medium?

Answer 1

${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$:

• ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ is the compound with the name Sodium thiosulfate.
• It is typically found in its pentahydrate form which is either white in color, or colorless altogether.
• This pentahydrate of sodium thiosulfate is described by the following chemical formula: ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3.5{\mathrm{H}}_2\mathrm{O}$.
• In its solid form, it is a crystalline solid which has a tendency to readily lose water.

n-factor:

• “The n factor of salts is defined as the number of moles of electrons exchanged (lost or gained) by one mole of the salt.”
• "n-factor is defined as the number of ${\mathrm{OH}}^{–}$ ions replaced by $1$ mole of the base in a reaction."

The total positive charge or total negative charge is $2$ with any basic medium.

So, the n-factor of sodium thiosulphate $\left({\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3\right)$ in the basic medium is $2$.