Question

What does each of the following look like when mixing each compound with water:

a) an insoluble ionic compound

b) an insoluble molecular compound

c) a soluble ionic compound

d) a soluble molecular compound

Answer 1

a)

• CO₃²⁻, C₂O₄²⁻, OH⁻, O²⁻, SO₃²⁻, PO₄³⁻, CrO₄²⁻, S²⁻ — all carbonates, oxalates, hydroxides, oxides, phosphates, chromates, and sulfides are insoluble. in water

b)

Almost all plastics, most oils, naphthalene (mothballs), sand, glass, soap scum (mostly calcium stearate, and related compounds), wax, pine pitch, mineral spirits, these are just a few.

c)

he structure of water makes it a polar molecule. This shows each hydrogen atom contain a slight positive charge, while the oxygen contain a slight negative charge.

Ionic compounds are crystalline in nature that contain the same number of both positive and negative ions. When you dissolve these ionic compounds in water, its molecules begin to attract water ions, which causes a separation between the ionic molecules. These atoms of hydrogen contained in water molecules are nearest to the ions of the compound with a negative charge, while the atoms of oxygen in the water molecule is nearest to the ions of ionic compounds with a positive charge.

examples - NaCl , KCl etc.

d)

Covalent bonds do not dissolve in water, but some covalent compounds do.

1

When an ionic compound like NaCl dissolves in water, we end up with Na⁺ ions and Cl⁻ ions in solution.

This is a dissolving process, because the original compound contained the same ions.

When a covalent compound like HCl dissolves in water, we end up with H₃O⁺ ions and Cl⁻ ions in solution.

Although the covalent H-Cl bond breaks, this is a reaction process in which the products are soluble.

It is not a solution process, because the particles in solution are different from those in the original solute.

Covalent molecules attract each other by various intermolecular forces. These include H-bonds, dipole-dipole forces, and London dispersion forces.

Water molecules attract each other by strong H-bonds.

A polar solute may attract the water molecules as strongly as the water molecules attract each other.

It should contain a highly electronegative atom such as N or O or, even better, an N-H or an O-H bond, because they can form H-bonds to the water molecules.

It will then be able to work its way among the water molecules (dissolve).

Sugar and ethanol are covalent compounds that are soluble in water, because they contain O-H groups that can H-bond to the water.