Final answer:
While solutions are homogeneous in their composition once mixed, it is false that they have a fixed composition in terms of solute concentration; different amounts of solute and solvent can be mixed to create solutions with varying concentrations.
Step-by-step explanation:
The question at hand asks whether solutions have a fixed composition, meaning that the amount of solute in a fixed amount of solvent is always the same. The answer to this question is false. Solutions can come in many concentrations, where the proportion of solute to solvent may vary.
However, once mixed, a solution is indeed homogeneous, meaning it will have uniform composition throughout the entire solution. The amount of solute does not change when more solvent is added, but the concentration of the solution does.
Therefore, different solutions of the same substances can have different solute concentrations depending on how much solute and solvent are present.
In summary, a solution is a homogeneous mixture in which the components are physically combined on a molecular scale, with every part of the mixture having the same composition.
Solutions commonly exist in a single physical state and the sum of mole fractions of all components equals one. Moreover, the component in the larger amount is the solvent and the one in the smaller amount is the solute.