Salad (lettuce,tomato,and onion) a pure substance or a mixture ?
The Correct Answer and Explanation is :
Salad, composed of ingredients like lettuce, tomato, and onion, is classified as a mixture rather than a pure substance. To understand this classification, it is essential to define the terms “pure substance” and “mixture.”
A pure substance consists of a single type of particle. This can be an element, like gold or oxygen, or a compound, like water (H₂O) or sodium chloride (table salt). Pure substances have consistent properties and compositions throughout. For example, a sample of pure water will always have the same chemical composition and characteristics, regardless of its source.
In contrast, a mixture contains two or more different substances that are physically combined but not chemically bonded. The components of a mixture retain their individual properties and can usually be separated by physical means, such as filtration or evaporation. Mixtures can be homogeneous (uniform composition) or heterogeneous (distinct, identifiable components).
In the case of a salad made of lettuce, tomato, and onion, each component maintains its unique properties and characteristics. Lettuce has a crisp texture, tomatoes are juicy and acidic, and onions have a strong flavor and aroma. When combined in a salad, these ingredients do not undergo a chemical change; instead, they coexist in a physical mixture.
Additionally, if you were to pick out the tomatoes or onions from the salad, you could do so easily, demonstrating that the ingredients are not chemically bound together. Therefore, a salad exemplifies a heterogeneous mixture, where the individual components are visually distinguishable and retain their original properties.
In conclusion, a salad is a mixture because it consists of multiple substances that are not chemically bonded, allowing for the distinct properties of each ingredient to remain intact.