Final answer:
The homogeneous solutions in the list provided are air, vinegar, and salt water. These substances maintain a uniform composition throughout, whereas cement and sand and water are heterogeneous mixtures with different compositions throughout.
Step-by-step explanation:
To determine which of the listed substances are homogeneous solutions, let's define a homogeneous solution as a mixture where the composition is uniform throughout. Comparing the substances:
- Air is a homogeneous mixture, as it is a mixture of gases that has uniform composition throughout.
- Vinegar is a homogeneous mixture because it is an acetic acid solution in water and the composition is consistent.
- Salt water is a homogeneous mixture; it is a consistent solution of salt dissolved in water.
- Cement is a heterogeneous mixture, as it contains various components that are not uniformly distributed.
- Sand and water form a heterogeneous mixture, because the sand does not dissolve and can be seen as a separate component within the water.
Thus, the homogeneous solutions from the list provided are air, vinegar, and salt water.