Give the classification of matter when two substances are present with heteroatomic molecules.
a) heterogeneous mixture
b) homogeneous mixture
c) compound
d) element
The correct answer and explanation is :
The correct answer is: a) heterogeneous mixture
Detailed Explanation:
Matter can be classified based on its composition and uniformity into different categories: elements, compounds, homogeneous mixtures, and heterogeneous mixtures.
When the question mentions “two substances” and “heteroatomic molecules,” let’s break it down carefully:
- “Two substances” means there are at least two different types of material present together.
- “Heteroatomic molecules” means the molecules are made up of different kinds of atoms (for example, H₂O, CO₂, or NH₃). However, the real focus here is the presence of two different substances, not just the type of molecule.
If two different substances are simply mixed together without undergoing a chemical reaction to form a new pure substance, the system is classified as a mixture. Mixtures are of two types:
- Homogeneous mixture: The composition is uniform throughout the sample. Examples include saltwater or air.
- Heterogeneous mixture: The composition is not uniform; you can see or separate different parts easily. Examples include salad, sand and iron filings, or oil and water.
Since the question specifies two substances are present and they are distinguishable (implied by the context of heteroatomic molecules not reacting into a single new compound), the matter is a heterogeneous mixture.
Now, why not the other options?
- Compound: A compound is a pure substance formed when two or more elements are chemically bonded together in a fixed ratio (like H₂O or NaCl). Here, substances are not chemically bonded, so it’s not a compound.
- Element: An element consists of only one type of atom. Since there are two substances and heteroatomic molecules (different atoms), it’s not an element.
- Homogeneous mixture: Although a homogeneous mixture contains multiple substances, they must be uniformly mixed. The question hints at the substances being distinguishable, so it’s not homogeneous.
Thus, a heterogeneous mixture is the correct classification when two substances are present and the system is not uniform.