Which aqueous solution has the highest boiling point at standard pressure

4. 2.0 M CaC12(aq)

Explanation:

According to the van't Hoff factor, (the measurement of the solute's colligative properties effect (boiling point,freezing point depression)) a solution that has the highest point at standard pressure, id the one with the most particles or ions.

van't Hoff factor can also be described as the ratio between the original concentration of the solutions's atoms when  the solution is dissolved and the concentration of the solutions taken from its mass.

The possible options are :

(1) 1.0 M KC1(aq) (3) 2.0 M KCl(aq) (2) 1.0 M CaC12(aq) (4) 2.0 M CaC12(aq)

Answer is (4) 2.0 M CaC12(aq)

Explanation:

vant Hoff factor highest BP has the most particles...ions CaCl2 forms 3 ==> Ca2+ and 2Cl-.

The van 't Hoff factor i (named after Dutch chemist Jacobus Henricus van 't Hoff) is a measure of the effect of a solute upon colligative properties such as osmotic pressure, relative lowering in vapor pressure, boiling-point elevation and freezing-point depression.

if you're asking what comes out, it's steam.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.