Chemical Purity:
* Definition: A substance is chemically pure when it contains only the specified elements or compounds in a defined ratio, without any impurities or contaminants.
* Calcium oxide: In its ideal form, calcium oxide is composed solely of calcium and oxygen atoms, adhering to the chemical formula CaO.
Practical Purity:
* Definition: This refers to the actual purity of a substance as found in the real world. It takes into account the presence of impurities, even if they are in small amounts.
* Calcium oxide: Even though calcium oxide is theoretically pure in its chemical structure, commercially available calcium oxide often contains some impurities like:
* Moisture: Calcium oxide is hygroscopic, meaning it readily absorbs moisture from the air, forming calcium hydroxide (Ca(OH)2).
* Carbon dioxide: Calcium oxide reacts with carbon dioxide in the air to form calcium carbonate (CaCO3).
* Other elements: Traces of other elements can be present depending on the manufacturing process.
Conclusion:
* Chemical purity: Calcium oxide is chemically pure, meaning it's ideally composed only of calcium and oxygen atoms.
* Practical purity: The practical purity of calcium oxide varies depending on its source and handling. It can contain impurities, even if they are in small amounts.
Therefore, while calcium oxide is chemically pure, its practical purity may be influenced by factors like moisture absorption and reactions with the surrounding atmosphere.
