Which of the following is a heterogeneous mixture?
A) ice and water
B) tap water
C) pure water
D) gasoline
The correct answer and explanation is :
The correct answer is A) ice and water.
Explanation:
A heterogeneous mixture is a mixture in which the components remain distinct and can be easily separated or identified. In contrast, a homogeneous mixture has a uniform composition throughout, and its components are not easily distinguishable.
- Ice and Water (Heterogeneous Mixture):
- Ice and water is a classic example of a heterogeneous mixture. When ice (solid water) is mixed with liquid water, the two phases remain separate. You can visibly see the ice cubes floating in the water, and they can be physically separated by melting the ice. The composition of the mixture is not uniform, as it consists of solid ice and liquid water, which retain their individual properties.
- The interaction between the solid and liquid phases is temporary. When the ice melts, the mixture becomes homogeneous, as the water will then be all in the liquid phase, with a uniform composition.
- Tap Water (Homogeneous Mixture):
- Tap water is a homogeneous mixture, even though it contains various dissolved minerals, salts, and sometimes gases. These substances are dissolved so completely in the water that you cannot distinguish one component from another without special testing. The composition is uniform throughout, making it a homogeneous mixture.
- Pure Water (Not a Mixture):
- Pure water (H₂O) is a compound, not a mixture. It has a fixed composition and consists entirely of water molecules. It does not have any other substances mixed in, and as such, it is neither heterogeneous nor homogeneous because it is not a mixture at all.
- Gasoline (Homogeneous Mixture):
- Gasoline is a homogeneous mixture of hydrocarbons. These compounds are mixed at the molecular level, and although gasoline may contain various additives, it appears uniform throughout. You cannot easily distinguish the components of gasoline with the naked eye.
In summary, ice and water is a heterogeneous mixture because it contains distinct phases (solid and liquid), while the other options are either homogeneous mixtures or pure substances.