Question

why do Polar covalent compounds dissolve in water

Answer 1

The Chemistry saying 'like dissolves like' is a guiding rule in determining which substance will dissolve in which. This saying means that Polar substances will dissolve polar substances and non-polar substances will dissolve non-polar substances. Polar and non-polar substances will not dissolve in one another. This is due to similar attractive forces between molecules.
For example; water is polar, so it can dissolve glucose and benzene which are also polar (all of them also exhibits Hydrogen Bonding). Whereas, water cannot dissolve oil or gasoline which are non-polar. But gasoline and oil, which have same attractive forces, dissolve very well in each other.
Hope this helps.

Answer 2

Polar covalent compounds dissolve in water.
This is because water is a polar covalent compound.
"Like dissolves like."
Also non-polar covalent compounds dissolve in non-polar covalent compounds (liquid)


Hope it helps................