Properties of Water: Why is Water Such a Good Solvent?

Why is water such a good solvent?

Properties of Water

A water molecule is formed when two atoms of hydrogen bond covalently with an atom of oxygen.

In a covalent bond electrons are shared between atoms. In water the sharing is not equal. The oxygen atom attracts the electrons more strongly than the hydrogen. T

his gives water an asymmetrical distribution of charge. Molecules that have ends with partial negative and positive charges are known as polar molecules.

It is this polar property that allows water to separate polar solute molecules and explains why water can dissolve so many substances.

Water is a good solvent due to its polarity.

Properties of Water

The solvent properties of water are vital in biology, because many biochemical reactions take place only within aqueous solutions.

When an ionic or polar compound enters water, it is surrounded by water molecules. The relatively small size of water molecules typically allows many water molecules to surround one molecule of solute.

The partially negative dipoles of the water are attracted to positively charged components of the solute, and vice versa for the positive dipoles.

An example of an ionic solute is table salt.

Liquid water has a partially ordered structure in which hydrogen bonds are constantly being formed and breaking up.

The strong hydrogen bonds also give water a high cohesiveness and, consequently, surface tension. This is evident when small quantities of water are put onto a non-soluble surface and the water stays together as drops.

Resources

Chemistry Experiments Involving Density - water is used as a basis for the experiments.

Investigating the Water Cycle Through Modeling - students construct two different models to investigate how a molecule of water moves throughout the transformation of states of matter called the water cycle.