Which of the following gases would you expect to deviate significantly from ideal behavior? [He, O2, H2, N2,H2O, HCl, NH3 -- Why?
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Example 1) Hydrochloric acid (HCl), will deviate the from ideal behavior because, we must take into account it's properties. HCl is a polar molecule (with it's molecular dipole moment pointing towards Chlorine, due it's higher pull on electron/electronegativity than hydrogen, creating a partial negative charge on the chlorine side and a partial positive charge in the hydrogen side). According to "Van der Waals" forces, forces between polar molecules can be either Dipole-Dipole or H-forces. In our case, it's Dipole-Dipole. WIf a lot of the HCl gases were get near each other (due to increased Pressure, which that in itself is a deviation from ideal behavior), they'll begin to form these invisible "Van der Waals" Dipole-Dipole forces.
**Any other polar gas (NH3 (g), H2O (g)) will deviate from ideal behavior based on the same principle mentioned (but may utilize H-forces, rather than Dipole-Dipole, depending on the type of elements present in the molecule itself).
**Gases behave less ideally at High pressures and Low temperatures (they behave less like how a gas is supposed to behave). Example: Just think of a cold coke can. It has dissolved gas in the liquid, do to the high pressure and low temperature allowing it to achieve properties less of a gas.
**Gases behave MORE ideally (more like a gas) at Low pressures and High temperatures.
**Any other polar gas (NH3 (g), H2O (g)) will deviate from ideal behavior based on the same principle mentioned (but may utilize H-forces, rather than Dipole-Dipole, depending on the type of elements present in the molecule itself).
**Gases behave less ideally at High pressures and Low temperatures (they behave less like how a gas is supposed to behave). Example: Just think of a cold coke can. It has dissolved gas in the liquid, do to the high pressure and low temperature allowing it to achieve properties less of a gas.
**Gases behave MORE ideally (more like a gas) at Low pressures and High temperatures.