1: Types of Solutions

Correct answer: A. True homogeneous dispersion of fine solid particles in air

Explanation: The combination of a solid solute and a gaseous solvent is described as solid in gas. It would count as a true solution only when the solid substance is dispersed at molecular or comparable microscopic scale and the mixture is genuinely homogeneous. Ordinary dust in air forms a heterogeneous aerosol, not a true solution, but the carefully worded possibility in A represents the classification. Therefore A is correct.

Correct answer: A. Check homogeneity, component count, solute-solvent roles, and states together

Explanation: A reliable solution strategy is to check the mixture’s homogeneity, count its components, identify solute and solvent, and note the state of each. These steps prevent common errors such as calling every mixture aqueous or deciding the type from the solute alone. Memorized examples can help, but the underlying method handles unfamiliar examples as well.

Correct answer: A. Binary and gas in gas

Explanation: The word binary describes the number of components, so two components make the solution binary. The phrase gas in gas describes the physical states of solute and solvent, since both are gases. These are independent bases of classification and can be used together. The other options contradict either the stated number of components or their states.

Correct answer: A. Ternary aqueous liquid solution

Explanation: Three components make the mixture ternary. Since water is the solvent, it is aqueous; because water is liquid, the broad physical category is liquid solution. Thus “ternary aqueous liquid solution” combines information about component count, solvent identity, and physical state. The other choices conflict with the stated three components or water solvent.

Correct answer: A. Chloroform in nitrogen

Explanation: A gaseous solution has a gaseous solvent. In chloroform in nitrogen, nitrogen is the gaseous solvent, while chloroform is treated as the liquid solute; hence it is liquid in gas, not gas in gas. Air and the listed gas mixtures contain gaseous components in a gaseous medium, so they represent gas-in-gas solutions.

Correct answer: A. Gas in solid and solid in gas

Explanation: The pair “gas in solid” and “solid in gas” contains the same two state words but assigns different roles to solute and solvent. In gas in solid, the gas is the solute and the solid is the solvent; in solid in gas, the solid is the solute and the gas is the solvent. Salt, sugar, and glucose in water are much less ambiguous because water is clearly the solvent.

Correct answer: A. Salt in water and camphor in nitrogen

Explanation: Salt and camphor are both solid solutes. In salt water, the solvent is liquid water, so the solution is liquid; in camphor in nitrogen, the solvent is gaseous nitrogen, so the solution is gaseous. Thus the category changes because the solvent state changes, even though the solute remains solid. The other pairs do not show this exact contrast.

Correct answer: A. Oxygen in water and hydrogen in palladium

Explanation: Oxygen and hydrogen are gaseous solutes in the two examples. Oxygen in water has a liquid solvent and therefore forms a liquid solution, while hydrogen in palladium has a solid solvent and forms a solid solution. This demonstrates that a gaseous solute can occur in different broad categories. The other options do not compare a gaseous solute with two different solvent states.

Correct answer: A. Ethanol in water and chloroform in nitrogen

Explanation: Ethanol and chloroform are liquid solutes in the two examples. With water as the solvent, ethanol in water is a liquid solution; with nitrogen as the solvent, chloroform in nitrogen is classified as a gaseous solution, specifically liquid in gas. Thus changing the solvent state changes the broad category even when the solute is liquid.