Select the statement(s) that is/are characteristic of ideal mixtures. 1. Obey Raoult's law 2. Have components with similar chemical structures 3. ΔH of mixing is zero

To determine the characteristics of ideal mixtures, we evaluate each statement:

1. Obey Raoult's law: An ideal mixture is defined as a solution that obeys Raoult's law over the entire range of concentrations and temperatures. This means the partial vapor pressure of each component in the mixture is directly proportional to its mole fraction. This statement is true.
2. Have components with similar chemical structures: For a mixture to be ideal, the intermolecular forces between the components (A-B interactions) must be similar in strength to the intermolecular forces within the pure components (A-A and B-B interactions). This often occurs when the components have similar molecular sizes, shapes, and polarities, i.e., similar chemical structures. This statement is true.
3. $\Delta \text{H}$ of mixing is zero: In an ideal mixture, there is no net change in enthalpy when the components are mixed. This means no heat is absorbed or released during the mixing process, as the energy required to break existing intermolecular bonds is equal to the energy released when new bonds are formed between the different components. This statement is true.

All three statements are characteristics of ideal mixtures.

The correct statements are:

1. Obey Raoult's law
2. Have components with similar chemical structures
3. $\Delta \text{H}$ of mixing is zero