When of alanine are dissolved in of a certain mystery liquid , the freezing point of the solution is lower than the freezing point of pure . On the other hand, when of potassium bromide are dissolved in the same mass of , the freezing point of the solution is lower than the freezing point of pure . Calculate the van't Hoff factor for potassium bromide in . Be sure your answer has a unit symbol, if necessary, and is rounded to the correct number of significant digits.

The factor is 2

Explanation:

Van't Hoff factor is defined as the ratio between the species of a solute before the addition to the solvent and particles produced when the substance is dissolved. It is used, principally, in colligative properties.

Before solution, potassium bromide, KBr, has just one specie, that is, KBr. When KBr is dissolved (As a salt):

KBr(aq) → K⁺(aq) + Br⁻(aq)

There are produced two species, K⁺ and Br⁻. By definition of Van't Hoff factor, for this salt, the factor is 2.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.