Solutions

Salt water has two chemical components: salt and water. Therefore, when classification is based on the number of components, it is a binary solution, making option A correct. It is not a pure substance because two substances are present, and it is not ternary because there are not three components. An alloy is generally a mixture involving metals, not this salt–water solution.

Sugar and water contain exactly two components, and if the sugar dissolves uniformly, they form a binary solution; therefore option A is correct. Salt, sugar and water contain three components and would be ternary if homogeneous. Air contains several gases, while an alloy of three metals has three metallic components, so neither is binary.

The mixture contains three distinct components: salt, sugar and water. Because the question states that it is homogeneous, the dissolved mixture is a solution with three components, called a ternary solution. Thus option B is correct. It cannot be binary because there are three components, and it is neither a pure substance nor a suspension.

In a gas-in-liquid solution, the gas is the solute because it dissolves, and the liquid is the solvent because it provides the dissolving medium. Therefore option A is correct. Carbon dioxide dissolved in water is a familiar example. Option B reverses the arrangement, C describes solid components, and D is false because solvents are not necessarily metals.

The phrase “liquid in gas” names the solute first and the solvent second. Thus a liquid solute is uniformly dispersed in a gaseous solvent, making option A correct. Option B describes gas in liquid, while C describes solid in liquid and D describes solid in solid. The classification depends on the physical states of solute and solvent.

The physical state of a solution is generally identified by the state of its solvent, because the solvent forms the continuous medium. Therefore, when the solvent is a gas, the resulting mixture is called a gaseous solution. A liquid or solid solute may be present, but it does not change this classification. “Aqueous” specifically means that water is the solvent, so option A is correct.

Brass is a homogeneous alloy formed mainly from the solid metals copper and zinc. In this example, the major solid metal acts as the solvent and the other solid component acts as the solute, so brass is treated as a solid solution. Soda water, salt water, and oxygen in water all contain liquid water as the solvent; consequently, they are not solid-in-solid solutions. Therefore option A is correct.

Salt water, sugar water, and soda water are liquid solutions because water is their liquid solvent and the dissolved substances are distributed uniformly throughout it. Brass is different: it is a homogeneous alloy made from solid metals, so it is classified as a solid solution. Thus brass is not a liquid solution. The state of the final solution is mainly determined by the state of its solvent, making option D correct.

Brass and bronze are solid alloys, and copper mixed uniformly into gold is also a solid-in-solid mixture. In each case, the solvent is a solid metal and the resulting solution remains solid. Sugar water is different: sugar is the solid solute, but water is a liquid solvent, so the result is a liquid solution. Therefore sugar water is not a solid solution, making option D correct.

Oxygen is a gas and water is a liquid. When oxygen dissolves in water, it forms a gas-in-liquid solution, so option A has exactly the required combination. Sugar in water is solid in liquid, zinc in copper is solid in solid, and water vapour in air is gas in gas because air is gaseous. Therefore only option A correctly matches a gaseous solute with a liquid solvent.

Glucose is a solid substance, while water is a liquid solvent. When glucose dissolves uniformly in water, the mixture is classified as a solid-in-liquid solution, so option A matches both required states. Carbon dioxide is a gas, ethanol is a liquid, and palladium is a solid containing gaseous hydrogen; therefore B, C, and D represent different state combinations. Option A is correct.

Ethanol is a liquid and water is also a liquid. They can mix uniformly, so ethanol in water represents a liquid-in-liquid solution. The component present in the smaller amount is generally called the solute, while the larger component is the solvent. Oxygen in water is gas in liquid, salt in water is solid in liquid, and zinc in copper is solid in solid. Thus option A is correct.

Air is a homogeneous gaseous mixture. Its major component, nitrogen, provides the continuous gaseous medium and is therefore treated as the solvent; oxygen and other gases are present as solutes. Salt water and soda water have liquid water as solvent, whereas brass is a solid alloy with a solid metallic solvent. Hence air is the only option showing a gaseous solvent situation, so A is correct.

Solution types are classified by the physical states of both components, such as gas in liquid, liquid in liquid, solid in liquid, or solid in solid. Identifying the states of solute and solvent therefore allows the example to be named and classified correctly. This information does not automatically change colour, remove mass, or convert a mixture into a pure substance. Hence option A gives the valid reason.

The governing concept is classification by the physical states of solute and solvent. In salt water, salt is a solid solute and water is a liquid solvent, so it is a solid-in-liquid solution. Brass is a solid alloy, not a liquid-in-gas example, while soda water contains a gas dissolved in a liquid. Therefore only option A correctly matches both the type and its example.

The governing convention is to name a solution by stating the solute state first and the solvent state second. Here the solute is solid and the solvent is gas, so the correct classification is solid in gas, expressed in Hindi as ‘गैस में ठोस’. Option A reverses the states; C assumes a liquid solvent, and D assumes a solid solvent. Hence B is correct.

The relevant rule is that the solute state is named first and the solvent state second. A gaseous solute dissolved in a solid solvent is therefore called a gas-in-solid solution. Hydrogen dissolved in palladium is a standard illustration: hydrogen is gaseous and palladium is solid. Options B, C, and D use the wrong order or the wrong solvent state, so A is correct.

The governing concept is classification by the solvent and solute states. In oxygenated water, oxygen is a gaseous solute; in salt water, salt is a solid solute. However, water is the solvent in both examples, and water is liquid. Thus both are liquid, aqueous solutions. Option B is false because the solutes have different states, while C and D give incorrect final states. A is correct.

The solvent is the continuous medium, and its state must be checked in every example. Soda water, salt dissolved in water, and ethanol dissolved in water all use water as the solvent; water is liquid in each case. The other options include air or nitrogen, whose solvent is gaseous, or brass and palladium, which are solid metallic media. Thus only A has a liquid solvent throughout.

To verify the condition, inspect the solvent in each example rather than the solute. Air is a gaseous mixture with a gaseous medium. In camphor in nitrogen and chloroform in nitrogen, nitrogen is explicitly the gaseous solvent. The other options contain water as a liquid solvent or metals such as brass and palladium as solid media. Therefore A is the only group in which every solvent is gaseous.

Air contains nitrogen, oxygen, argon, carbon dioxide, water vapour, and other gases in variable proportions. When these gases are uniformly mixed, air behaves as a homogeneous gaseous mixture, commonly described at this level as a gas-in-gas solution. It is neither a pure substance nor only oxygen.

Aqueous means that water is the solvent. The solute may be solid, liquid, or gas: salt, alcohol, and oxygen can all form aqueous solutions when they dissolve in water. Since water is generally liquid, aqueous solutions are commonly liquid, but the definition does not say they are always solid. Salt water is a valid aqueous solution. Therefore the incorrect statement is C.

A solution is a homogeneous mixture, not simply any mixture containing two substances. Its components must be uniformly distributed and form one phase at the relevant scale. Oil and water, for example, contain two substances but form separate layers, so they are not a true solution.

The governing concept is that a solution is described by the physical states of its solute and solvent. In salt water, salt is a solid solute and water is a liquid solvent, so it is a solid-in-liquid solution. Therefore option D is incorrect. Air is gas in gas, brass is solid in solid, and carbon dioxide in soda water is gas in liquid, so A, B, and C are correctly paired.

In an ordinary solution, the solvent usually determines the physical-state description of the final solution. Carbon dioxide is a gas, whereas water is a liquid, so carbon dioxide dissolved in water is treated as a liquid solution; its state differs from the gaseous solute and matches the liquid solvent. In B both are gases, in C both are solids, and in D both are liquids.