Which of these solutions has the highest boiling point?

Question

Which of these solutions has the highest boiling point?

	2 M HCl
	2 M CaO
	2 M NH3
	2 M CaBr2

(Thank you kindly in advance)!

Answer 1

2M CaBr2 has the highest boiling point. This is because CaBr2 is an ionic compound that dissociates into three ions when dissolved in water, which increases the boiling point of the solution.

Answer 2

A good rule of thumb is the more ions, and the stronger the charge of the ions, the higher the boiling point

2M CaBr₂ splits into Ca²⁺ and 2 Br^- ions

HCl and CaO are both ionic, but CaO will not dissolve in water, and HCl splits up into two ions (H+ and Cl-).

NH₃ is not an ionic compound.

For these reasons, CaBr₂ will increase the boiling point the most.