Question

The data in the table below are for the ionic substances, when they are placed in water at 298K and 1 bar:

AB (s) + H₂O(l) --> A^positive(aq) + B ^negative(aq), where AB(s) is either NaCl, CaCl₂, or BaSO₄

∆H⁰_solution (kJ/mol)  ∆S⁰_solution (J/K mol)  ∆G⁰_solution (kJ/ mol)

              NaCl       +3.6                     +42.7                         – 9.1

              CaCl₂   – 81.4                    – 47.6                         – 67.2

              BaSO₄   +26.2                   –104.1                         +57.2

If AB does not dissolve, then AB is

	a.	BaSO4
	b.	NaCl
	c.	none of these compounds
	d.	CaCl2

Answer 1

The answer for the above question i.e.

AB (s) + H2O(l) --> A+(aq) + B-(aq)

and AB does not dissolve, then( according to above given options and data) AB is CaCl2

Therefore correct option is option