Explain why sea water is a mixture whereas purified water is not.

Understanding the Terms: To answer this question, we first need to understand what a mixture is. A mixture is a substance made by combining two or more different materials in such a way that no chemical reaction occurs. This means each of the substances retains its own chemical properties. On the other hand, a pure substance has a constant composition with fixed ratios of particles and cannot be separated into different types of molecules by physical means.

Sea Water as a Mixture: Sea water is considered a mixture because it contains many different substances. It is primarily composed of water, but it also contains a variety of other components such as salts (mostly sodium chloride), minerals, and even living organisms. Each of these components retains its own chemical properties, making sea water a mixture.

Purified Water is Not a Mixture: Purified water, on the other hand, is not a mixture because it has been processed to remove all impurities and contaminants. This means it consists of only one type of molecule, H2O, and does not contain any other substances. Therefore, it is not a mixture but a pure substance.

Conclusion: So, sea water is a mixture because it contains a variety of different substances that retain their own chemical properties, while purified water is not a mixture because it consists of only one type of molecule.