Pure Substance vs Mixture

Seawater, cooking oil, steel, bronze, oxygen, salt, soil – when you look at these things individually, do you think that you can recognize whether they fall under the ‘pure substance’ or ‘mixture’ category? Let us learn about the distinct differences and similarities, if any, between a pure substance and a mixture.

Firstly, a pure substance is matter which cannot be separated into any other kind of matter when using the physical or chemical process. All the particles which make up a pure substance have the same color, taste, composition and texture. In other words, it can be an element or a compound, which consists of only one component with a definite composition, chemical and physical properties.

Secondly, a mixture is a combination of two or more substances which are not united using a chemical procedure. The components that make up a mixture do not exist in fixed proportions, and most of the natural substances that you are familiar with, are mixtures. Examples of mixtures include water, alcohol, oil, and dye.

So what are the distinct differences between these two? With regards to a mixture, it can be physically separated into pure compounds or elements. This is something that is not possible with a pure substance, because it is already a type of matter which exists in its most basic, or purest form.

Another distinct characteristic of a pure substance is that, no matter how physically impossible it may be to isolate a pure substance, it can only be considered as pure if no impurities are detected. When it comes to their physical properties, such as their boiling or melting points, pure substances are non-changing, while mixtures are varying. For example, the boiling point of pure water is at 100 degrees Celsius, while the boiling point of alcohol mixed with water may be at a range of temperatures. To put it simply, pure substances are exactly what the name implies – pure, while mixtures are impure.

Summary:

1. Pure substances cannot be separated into any other kinds of matter, while a mixture is a combination of two or more pure substances.

2. A pure substance has constant physical and chemical properties, while mixtures have varying physical and chemical properties (i.e., boiling point and melting point).

3. A pure substance is pure, while a mixture is impure.