Understanding Homogeneous Mixtures

A homogeneous mixture is a type of mixture where the substances are mixed evenly throughout. This means the mixture has a uniform composition and appearance. You can't see the different components with the naked eye. Common examples include saltwater or air.

A heterogeneous mixture, on the other hand, is not uniform. The different components are visibly distinguishable, or the composition varies from one part of the mixture to another. Oil and water is a classic example.

Analyzing the Options Provided

Let's examine each mixture listed in the question:

• i. Salt in water: When salt (sodium chloride, NaCl) dissolves in water, the salt particles spread out evenly among the water molecules. The resulting saltwater looks the same throughout and tastes salty everywhere. This is a homogeneous mixture.
• ii. Sugar in water: Similar to salt, sugar dissolves completely in water, forming a uniform solution. The sugar molecules disperse evenly, making the mixture homogeneous. This is a homogeneous mixture.
• iii. Oil and water: Oil and water do not mix. When combined, they separate into distinct layers. You can easily see the boundary between the oil and the water. This is a classic example of a heterogeneous mixture.
• iv. Copper sulphate in water: Copper sulphate (CuSO₄) dissolves in water to form a uniformly blue-colored solution. The copper sulphate particles are evenly distributed throughout the water, making it a homogeneous mixture.

Identifying the Homogeneous Mixtures

Based on the analysis:

• Mixture i (Salt in water) is homogeneous.
• Mixture ii (Sugar in water) is homogeneous.
• Mixture iii (Oil and water) is heterogeneous.
• Mixture iv (Copper sulphate in water) is homogeneous.

Therefore, the homogeneous mixtures listed are i, ii, and iv.

Conclusion

The question asks to identify which of the listed items are homogeneous mixtures. Based on our analysis, salt in water (i), sugar in water (ii), and copper sulphate in water (iv) are all homogeneous mixtures because their components are uniformly distributed throughout.