Why is water a universal solvent?

Water can dissolve more chemical substances than any other solvent because of its polar nature and hydrogen bonding formation ability. The vast interaction formation ability, the specific bond angles within a molecule, a high electronegativity difference, make water unique and a universal solvent.

The solvent nature of water has one parameter of polarity. Hydrogen atoms of water molecules are bonded with oxygen atoms at the angle of 104.5 °. This bent nature becomes a cause for geometrical polarity.

Furthermore, oxygen being highly electronegative (EN = 3.60 out of 4.00 at the Pauling scale) attracts the shared pairs of electrons towards itself. This makes hydrogen atoms of water partially positive and highly interactive. The same reactivity is seen in oxygen atoms because of the high electron density or basicity. This is the reason why strong intermolecular forces are present in water. When a polar or slightly polar solute is added, water molecules start encapsulating it with hydrated bonds.

Hydrogen bond formation ability corresponds only to the hydrogen atoms combined with highly electronegative atoms i.e. (O, N, and F). The oxygen of water being one of the highly electronegative ones enables water to form hydrogen bonds.

Due to the above-mentioned factors, water is capable to dissolve ionic lattices.

Why does NaCl dissolve in water?

Why does NaBr dissolve in water?

Along with ionic compounds, water also dissolves some of the organic compounds, where interaction formation capacity or polarity is present.

Why does sugar dissolve in water?

Although, there are exceptions to this universal solubility trend. Non-polar compounds especially the ones with absolutely no dipole moment refuse to dissolve in water. Mostly organic compounds e.g. hydrocarbons are insoluble in water.

Why are hydrocarbons insoluble in water?

Due to similar reasons, the oils (especially organic) do not dissolve in water. The density difference between water and oils makes oils float over water in most cases.

Why does oil float on water?

If these exceptions are ruled out, water is considered to be an ideal solvent. As nothing can be ideal, these reasons serve the purpose to make water a little less ideal solvent.

Universal solvent and biochemical processes

Water being a universal solvent plays a pivotal role in most biochemical reactions.

All chemical reactions to extract and flush out unwanted chemical salts such as ALT, ALPs, and uric acid are filtered by kidneys, and then by dissolution in water, we can only get rid of them.

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