Solute and solvent

The physical class of a solution is normally named from the state of its solvent. Therefore, when the solvent is solid, the mixture is classified as a solid solution. This information alone does not reveal whether the solute is solid, liquid, or gas. It also cannot prove that water is present, so the other conclusions are unjustified.

In soda water, carbon dioxide is the gaseous solute, water is the liquid solvent, and the resulting solution is liquid. This gives the sequence gas, liquid, liquid exactly as required. Brass has solid components, air has gaseous components, and salt water has a solid salt solute, so B, C, and D assign incorrect solute states. Thus option A is correct.

When both components have the same physical state, state alone cannot identify the solute and solvent. The usual school-level rule is to compare their amounts: the component present in greater amount is generally called the solvent, while the smaller component is the solute. Therefore A is correct. Colour, alphabetical order, and smell may vary, but none of them defines these roles.

In soda water, water is the solvent and it is liquid; carbon dioxide is the gaseous solute. Hence soda water is a gas-in-liquid solution and does not have a solid solvent, so option A is correct. Brass has a solid metal solvent, hydrogen dissolves in solid palladium, and mercury dissolves in solid sodium. Those three examples therefore have solid solvents.

A homogeneous solution has a uniform composition throughout the sample because its solute is evenly distributed in the solvent. Therefore, the claim that composition differs in every small part contradicts homogeneity, making option A the least suitable statement. Options B and C describe uniform distribution and appearance, while D correctly identifies the solvent as the dissolving medium.

The governing concept is that the physical state of a solution is generally identified by its solvent, while the solute may have a different state. In option A, carbon dioxide is a gaseous solute and water is a liquid solvent, so the result is a gas-in-liquid, liquid solution. In B, C, and D, the solvents are gases, so those mixtures are gaseous solutions.

The relevant principle is classification by the physical states of the solute and solvent. In option A, oxygen is the gas solute and nitrogen is the gas solvent, so the mixture is a gas-in-gas solution. Option B is gas in liquid, option C is gas in solid because palladium is solid, and option D is solid in liquid because glucose is solid and water is liquid.

A solid-in-solid solution has a solid solute uniformly incorporated into a solid solvent. In option A, zinc is the solid solute and copper is the solid solvent; together they can form a solid alloy or solid solution. Oxygen in water is gas in liquid, sugar in water is solid in liquid, and ethanol in water is liquid in liquid, so none of those matches.

The defining condition is a liquid water solvent combined with a gaseous solute. Option A satisfies both conditions: oxygen is a gas and it can dissolve in water, producing a gas-in-liquid aqueous solution. Salt and sugar are solid solutes, whereas ethanol is a liquid solute. Thus the other choices have water as solvent but fail the required state of the solute.

The governing concept is that the overall physical state of a solution generally follows the state of its solvent, not merely the state of its solute. For example, salt is a solid solute, but salt water is a liquid solution because water is liquid. Therefore A identifies the mistake. B repeats the misconception, while C and D incorrectly deny dissolution or the solvent’s role.

An aqueous solution specifically has water as its solvent. In salt water, water is also liquid, so the same sample is both aqueous and a liquid solution; salt is the solute. Hydrogen in palladium and zinc in copper have solid solvents, while air is a gaseous mixture without water as its solvent. Therefore only option A has both required classifications.

In salt water, salt is the substance that dissolves, so it is the solute. Water provides the medium and is therefore the solvent. Option A reverses these roles. The other statements correctly identify the dissolved substance or the larger component as solute or solvent.

The governing rule is that a solution is classified mainly according to the physical state of its solvent. Glucose is a solid solute, but water is a liquid solvent; therefore glucose dissolved in water forms a liquid solution, not a solid solution. Zinc in copper, copper in gold, and carbon in zinc are solid-in-solid examples because their solvents are solid metals. Hence A is correct.

The naming convention lists the solute first and the solvent second. The question states that the solute is liquid and the solvent is solid, so the correct category is liquid in solid solution. Option B reverses both roles and describes a solid solute in a liquid solvent. Options C and D involve gaseous solutes, which do not match the stated liquid solute. Thus A is the only correct choice.

The governing convention for describing solution types is solute first and solvent second. For example, salt dissolved in water is called a solid-in-liquid solution because salt is the solid solute and water is the liquid solvent. Option B reverses the component order, while C and D give unrelated properties rather than solution components. Therefore A states the correct naming order.

A solution is called aqueous when water is its solvent. In this case, salt and sugar are the solutes and water remains the solvent, so the mixture is an aqueous solution even though two different solutes are present. The number of solutes does not alter the solvent-based name. B would require a solid solvent, C a gaseous solvent, and D a solvent other than water. Therefore A is correct.

The governing concept is that an aqueous solution specifically has water as its solvent. Here iodine is the solute and ethanol is the solvent; because ethanol is not water, the mixture is classified as a non-aqueous solution. The small amount of iodine affects quantity, not the classification. It is not gaseous because ethanol is liquid, and it is not a solid solution because the solvent is not solid. Thus A is correct.

The relevant principle is to compare the solute and solvent in each pair. In salt water, salt is a solid solute; in oxygenated water, oxygen is a gaseous solute. In both cases, water remains the liquid solvent, so only the solute state changes. The other options do not keep water as the common solvent: brass and bronze are solid alloys, air and smoke are gas-containing mixtures, and D uses solid metallic solvents.

In the expression “solid in liquid,” the first state refers to the solute and the second state refers to the solvent. Therefore the solute is solid and the solvent is liquid. Salt dissolved in water is a familiar example. The other choices reverse the order or give unrelated states.

In expressions such as “liquid in solid,” the first state names the solute and the second state names the solvent or medium. Therefore “liquid in solid” means a liquid solute uniformly distributed in a solid solvent. It does not mean a solid solute in a liquid solvent; that reverse combination would be called “solid in liquid.”

In soda water, carbon dioxide is dissolved in water. Water is the liquid solvent, so the mixture is classified as a liquid solution, more specifically a gas-in-liquid solution. Air is gas in gas, brass is a solid alloy and therefore a solid solution, and hydrogen in palladium is gas in solid. Hence only the first pairing is correct.

Camphor is the solid solute, but nitrogen is the gaseous solvent. The broad category is determined by the solvent, so camphor in nitrogen is a solid-in-gas or gaseous solution, not a liquid solution. Air is gas in gas, brass is solid in solid, and salt water is solid in liquid. Thus option D is the incorrect match.

The solute is the component that gets dissolved in the solvent and is commonly present in the smaller amount. “Generally” is important because the roles depend on the mixture, especially for two liquids. A solute need not be a gas or water; salt, ethanol, oxygen, and metals can all act as solutes in suitable solutions.

The solvent is the medium in which the solute dissolves and is usually present in the greater amount. Its physical state generally determines whether the final solution is classified as solid, liquid, or gas. Brightness, smell, and container shape do not define a solvent, and water is not the solvent in every solution.

Brass is a homogeneous alloy made mainly by combining solid metals, commonly copper and zinc. In the classification used here, one solid metal acts as the solvent and the other as the solid solute, giving a solid-in-solid solution. Soda water and oxygen in water have liquid solvents, while camphor in nitrogen has a gaseous solvent.