Is carbon monoxide a pure substance or a mixture?
The Correct Answer and Explanation is:
Carbon monoxide (CO) is a pure substance. It consists of only one type of molecule, which is made up of one carbon atom and one oxygen atom bonded together. A pure substance is defined as a material that has a constant composition and can either be an element or a compound. Carbon monoxide fits this definition as it is a chemical compound formed when carbon combines with oxygen in a 1:1 ratio.
To understand this better, let’s break it down:
- Definition of a pure substance: A pure substance has a uniform and fixed composition. It cannot be separated into other substances by physical means. Examples include elements like oxygen (O2) or compounds like water (H2O), both of which are pure substances.
- How CO fits the definition: Carbon monoxide is a compound, not an element. It is made up of two elements—carbon (C) and oxygen (O)—but the ratio and chemical bonds between the atoms are fixed. This means it has a specific, constant molecular composition, which is characteristic of a pure substance. In the case of carbon monoxide, each molecule is made up of one carbon atom and one oxygen atom, chemically bonded.
- Mixtures vs. pure substances: A mixture, on the other hand, consists of two or more substances that are physically combined but not chemically bonded. In mixtures, the components can be present in varying proportions and can usually be separated by physical methods like filtration or distillation. An example of a mixture is air, which contains nitrogen, oxygen, carbon dioxide, and other gases.
Since carbon monoxide does not vary in its composition and cannot be separated into simpler components through physical means, it qualifies as a pure substance.
