Final answer:
To determine if a gas is pure, one can analyze its unique emission spectrum, a series of colors emitted when the gas is heated and which correspond to the gas's unique atomic structure. To evaluate if a gas is ideal, one can conduct experiments measuring pressure, volume, and temperature, and plot these variables to see if they align with the Ideal Gas Law.
Step-by-step explanation:
To ascertain if a gas is pure from a diagram or an experiment, you can examine the emission spectrum of the gas. When a substance is heated, it emits light that can be passed through a diffraction grating to separate it into a spectrum of colors, which is unique to each element. This means that a pure gas will exhibit a specific pattern of spectral lines. For example, pure hydrogen emits a different pattern of colors when compared to pure sodium. If a gas is a mixture of elements, it will display multiple patterns of spectral lines. This principle is similar to how a person's unique signature can identify them.
In the case of evaluating whether a gas behaves as an ideal gas, scientists can design an experiment measuring variables such as pressure, volume, and temperature. They then plot these measurements on a graph. An ideal gas would show a linear relationship between variables that matches the predictions of the Ideal Gas Law (PV=nRT). By plotting data points and drawing a best-fit line, one can determine if the graph's characteristics conform to those of an ideal gas. For instance, if plotting pressure against 1/volume at constant temperature yields a straight line, it suggests that the gas exhibits properties of an ideal gas.