1. Which statement best defines a solution?
ⓐ. A solution is a homogeneous mixture of two or more components.
ⓑ. A solution is a compound formed in a fixed mass ratio.
ⓒ. A solution is any mixture in which one substance is always liquid.
ⓓ. A solution is a heterogeneous system with visible layers.
Correct Answer: A solution is a homogeneous mixture of two or more components.
Explanation: A solution has a uniform composition throughout the sample, so it is a homogeneous mixture. Its components are physically mixed, not chemically combined in a fixed ratio as in a compound.
2. Which feature most clearly distinguishes a solution from a heterogeneous mixture?
ⓐ. A solution has uniform composition throughout.
ⓑ. A solution always contains water.
ⓒ. A solution contains only one phase because it is a pure substance.
ⓓ. A solution must be made from two liquids only.
Correct Answer: A solution has uniform composition throughout.
Explanation: Uniform composition is the key identifying feature of a solution. In a heterogeneous mixture, composition is not the same throughout the sample, so different portions can differ in properties.
3. Which statement correctly compares a solution with a pure substance?
ⓐ. Both always contain only one kind of particle.
ⓑ. A pure substance has variable composition, but a solution has fixed composition.
ⓒ. A solution has fixed composition, but a pure substance does not.
ⓓ. Solutions have variable composition; pure substances have fixed composition.
Correct Answer: Solutions have variable composition; pure substances have fixed composition.
Explanation: The composition of a solution can change from one sample to another by changing the relative amounts of its components. A pure substance, however, has a definite and fixed composition.
4. Which of the following is definitely a solution?
ⓐ. Mud in water
ⓑ. Oil and water
ⓒ. Air
ⓓ. Smoke
Correct Answer: Air
Explanation: Air is a homogeneous mixture of gases and is therefore a solution. Mud in water, oil and water, and smoke are not uniform throughout in the same way.
5. Which statement is correct for a true solution?
ⓐ. Different parts of the sample may have different compositions.
ⓑ. The components remain uniformly distributed at the macroscopic level.
ⓒ. The sample must contain only one chemical substance.
ⓓ. The mixture must show separate visible boundaries between components.
Correct Answer: The components remain uniformly distributed at the macroscopic level.
Explanation: In a true solution, the composition is uniform from one part of the sample to another. This is why a solution appears as a single homogeneous phase in ordinary observation.
6. Which sample is not a solution?
ⓐ. Salt dissolved in water
ⓑ. Vinegar
ⓒ. Brass
ⓓ. Sand in water
Correct Answer: Sand in water
Explanation: Sand in water does not form a homogeneous mixture. The components remain non-uniformly distributed, so it is not a solution.
7. Which statement about solutions is incorrect?
ⓐ. A solution is always homogeneous.
ⓑ. A solution may contain more than one component.
ⓒ. A solution has the fixed composition of a pure compound.
ⓓ. A solution may exist in forms other than liquid systems.
Correct Answer: A solution has the fixed composition of a pure compound.
Explanation: A solution does not have a fixed composition like a pure compound. Its composition depends on how much of each component is present, although the mixture remains homogeneous.
8. In the study of solutions at this level, the main quantitative emphasis is usually placed on
ⓐ. solid solutions only
ⓑ. all mixtures equally, without special focus
ⓒ. gaseous solutions only
ⓓ. liquid solutions
Correct Answer: liquid solutions
Explanation: Solutions can exist in gaseous, liquid, and solid forms, but most standard quantitative relations such as concentration terms, vapour pressure relations, and colligative properties are developed mainly for liquid solutions.
9. A sample of sugar dissolved completely in water appears identical throughout the container. This observation shows that the mixture is
ⓐ. a pure liquid with fixed composition
ⓑ. a heterogeneous mixture with two visible phases
ⓒ. a homogeneous mixture with uniform composition
ⓓ. a suspension with settling particles
Correct Answer: a homogeneous mixture with uniform composition
Explanation: Uniform appearance throughout the sample indicates homogeneity. When every macroscopic part of the mixture has the same composition, the system is called a solution.
10. Which statement about a solution is correct?
ⓐ. Its composition is always fixed like that of a compound.
ⓑ. Its components are uniformly distributed in a single phase.
ⓒ. Its particles must always be solids dissolved in a liquid.
ⓓ. Its components can be separated only by a chemical reaction.
Correct Answer: Its components are uniformly distributed in a single phase.
Explanation: A solution is identified by uniform distribution of its components. Its composition may vary, and its components are physically mixed rather than chemically combined into a fixed-composition substance.
11. Which of the following can form a solution even though it is not a liquid system?
ⓐ. oil and water mixture
ⓑ. sand and water mixture
ⓒ. chalk and water mixture
ⓓ. an alloy such as brass
Correct Answer: an alloy such as brass
Explanation: Solutions are not limited to liquids. A homogeneous solid mixture such as brass is a solid solution, whereas oil and water, sand and water, and chalk and water are not homogeneous solutions.
12. Which statement is false for a solution?
ⓐ. It is homogeneous at the macroscopic level.
ⓑ. It may contain more than one component.
ⓒ. It always consists of two components only.
ⓓ. It can have variable composition.
Correct Answer: It always consists of two components only.
Explanation: A solution may contain two components or more than two components. The essential feature is homogeneity, not the requirement that the number of components must always be exactly two.
13. In a solution, the component present in larger amount is generally called the
ⓐ. precipitate
ⓑ. solute
ⓒ. colloid
ⓓ. solvent
Correct Answer: solvent
Explanation: The solvent is usually the component present in larger amount and acts as the medium in which the other component is dissolved. The solute is generally present in smaller amount.
14. Which statement correctly identifies solute and solvent in a usual solution?
ⓐ. Solute is the major component and solvent is the minor component.
ⓑ. Solute and solvent must always be in equal amount.
ⓒ. Solvent is the component that dissolves, and solute is the medium.
ⓓ. Solute is generally the component present in smaller amount.
Correct Answer: Solute is generally the component present in smaller amount.
Explanation: In ordinary terminology, the solute is the component present in lesser amount and the solvent is present in greater amount. This relative-amount criterion is the usual way to distinguish the two terms.
15. A solution containing exactly two components is called
ⓐ. a saturated solution
ⓑ. a binary solution
ⓒ. a colloidal solution
ⓓ. a supersaturated solution
Correct Answer: a binary solution
Explanation: The word binary means two-component. So, a solution made up of exactly two components is called a binary solution.
16. In a binary solution of alcohol and water containing much more water than alcohol, water is the
ⓐ. solute
ⓑ. dispersed phase
ⓒ. suspended solid
ⓓ. solvent
Correct Answer: solvent
Explanation: Since water is present in larger amount, it is treated as the solvent. Alcohol, being present in smaller amount, is the solute in this binary solution.
17. Carbon dioxide dissolved in water in a soft drink is best described as
ⓐ. water as solute and carbon dioxide as solvent
ⓑ. both as solvents because both are fluids
ⓒ. carbon dioxide as solute and water as solvent
ⓓ. both as solutes because the composition can vary
Correct Answer: carbon dioxide as solute and water as solvent
Explanation: Here water is the major component and serves as the solvent. Carbon dioxide is dissolved in it in a smaller amount, so it is the solute.
18. Which statement about solute and solvent is incorrect?
ⓐ. The solvent usually provides the medium of the solution.
ⓑ. The solute is always identified by having a lower molar mass.
ⓒ. In usual cases, the solvent is present in greater amount.
ⓓ. In a binary solution, one component acts as solute and the other as solvent.
Correct Answer: The solute is always identified by having a lower molar mass.
Explanation: Solute and solvent are not identified by molar mass. The usual distinction is based on relative amount: the solvent is generally present in larger amount, while the solute is present in smaller amount.
19. In a solution formed by dissolving a small amount of iodine in a much larger amount of alcohol, alcohol is called the
ⓐ. solute
ⓑ. dispersed phase
ⓒ. solvent
ⓓ. suspended part
Correct Answer: solvent
Explanation: The component present in larger amount is generally called the solvent. The smaller amount of iodine is the solute, while alcohol provides the medium of the solution.
20. Which statement correctly defines a binary solution?
ⓐ. It contains exactly two components.
ⓑ. It contains two visible phases.
ⓒ. It contains one solute and two solvents.
ⓓ. It contains only liquid components.
Correct Answer: It contains exactly two components.
Explanation: A binary solution is defined only by the number of components present. If the solution has exactly two components, it is called binary, regardless of their physical states.
