Answer : Option C) ionic sodium phosphate [tex] (Na_{3}PO_{4})[/tex]
Explanation : Amongst the given choices the ionic molecule of sodium phosphate will dissociate into the most ions in the water and it is the number of particles that affect the raising of boiling point or depression of freezing point.
As this property is dependent on the ratio of number of molecules of solute dissolved in number of solvent molecules in a solution, and not on the nature of the chemical species present which is called as a colligative property.
As the [tex] Na_{3}PO_{4} --> 3Na_^{+} + PO_{4}^{3-} [/tex]
Total there are 4 ions produced, which is higher than others.
[tex] LiCl ----> Li^{+} + Cl^{-} [/tex] which gives only 2 ions;
[tex] NaCl ----> Na^{+} + Cl^{-} [/tex] this gives 2 ions;
[tex] C_{12}H_{22}O_{11} ---> C_{12}H_{22}O_{11}[/tex] it gives only 1 molecule not ions.
[tex] MgBr_{2} ---> Mg^{2+} + 2 Br^{-} [/tex] it gives in all 3 ions.
So, the correct answer is ionic sodium phosphate which gives maximum number of ions when dissolved in water.
