Identify each of the following as a pure substance or a mixture: give details
A. pasta and tomato sauce
B. aluminum foil
C. helium
D. air
The Correct Answer and Explanation is :
Let’s break down the classification of each substance based on whether it is a pure substance or a mixture:
A. Pasta and Tomato Sauce – Mixture
Pasta and tomato sauce form a mixture, specifically a heterogeneous mixture. A heterogeneous mixture is one where the components are not uniformly distributed, and you can visibly see the different substances. In this case, you can see the distinct pasta and tomato sauce components that do not combine chemically. Each retains its properties and can be separated physically (such as by draining the sauce off the pasta). The ingredients in the sauce might also vary, adding to the non-uniformity of the mixture.
B. Aluminum Foil – Pure Substance
Aluminum foil is considered a pure substance, specifically an element. It is made entirely of aluminum (Al) atoms, and there are no other types of atoms or molecules involved. It does not need to be separated into different components, as it is in its elemental form. A pure substance has a uniform and fixed composition throughout, and in the case of aluminum foil, it remains the same regardless of how it’s manipulated.
C. Helium – Pure Substance
Helium (He) is also a pure substance. It is a chemical element, composed entirely of helium atoms. Pure substances have a consistent and fixed chemical composition, and helium is no exception. In its natural state, helium exists as a single type of atom, and it does not need to be separated or combined with anything else to form a different substance.
D. Air – Mixture
Air is a mixture, specifically a homogeneous mixture. It consists of several gases, primarily nitrogen (N₂), oxygen (O₂), argon (Ar), carbon dioxide (CO₂), and trace amounts of other gases. Although air is uniform in appearance, its composition can vary depending on location and other factors (such as pollution). Because air is made up of different substances that are not chemically bonded, it is considered a mixture.
Explanation:
- Pure substances are made up of only one kind of element or compound, and their composition is uniform throughout. They cannot be separated by physical means.
- Mixtures, on the other hand, contain two or more different substances that are physically combined, and these components retain their own properties. Mixtures can be separated into their components by physical methods.
Now, let me generate an image for this classification.
Here’s the educational illustration that categorizes each of the items as either a mixture or a pure substance. It should help you visualize the differences between them. Let me know if you need further clarification!
