When doing a recrystallization what observations would prompt you to perform a hot filtration?

I would do a hot filtering if I observed that I was facing a situation where crystallization occurs in a hot solution, but decrystalization occurs in a cold solution.

Explanation:

The hot filtration method is generally employed in solids purification processes (solids mixing), also called recrystallization purification. In general, hot filtration is associated with the vacuum filtration method.

The hot filtration method uses the principle of different solubility at different temperatures, ie a substance is hot soluble in one solvent but not soluble in the same solvent at room temperature. In the hot solvent, only one substance in the mixture dissolves completely, the other substance remains insoluble and is retained by the filter. When the filtered solution cools, the insoluble substance is separated from the solvent.

In this case, it is only favorable to use hot filtration if you observe that crystallization of a particular material occurs in a hot solution and its dissolution occurs in cold solution.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance