Question

How does the principle of "like dissolves like" explain the different solubilities of solutes in various solvents?

and

What amount, in grams solute per 100 mlL solvent, classifies a solute eas being "souble" in a particular solvent?

Answer 1

A)
Like dissolves in like means polar compounds tend to dissolve in polar solvents and that non-polar compounds tend to dissolve in non-polar solvents. Polar solvent includes H2O and non polar includes oil .So oil won't dissolve in water because oil consists of non-polar long-chain hydrocarbon molecules, and water is polar.
Bond iis basically electrostatic force of attraction. So if two polar molecules are near each other, there is attraction force between their positive end of one and negative part pof other. So they form bond. In contrast, the oil molecules aren't polar (don't have positively or negatively charged areas), so if a water molecule is next to an oil molecule, these bonds can't be formed.
For example, glucose is polar and very water soluble but not soluble in oils. Vitamin A or beta-carotene is not water soluble, but will dissolve in fats and oils, which are also non-polar.

B)
Solubity depends on solubility product. So I dont think there is a predefined way to say how many grams can dissolve in 100 mL to clasify them as soluble