If you want more info regarding data storage, please contact gdpr jove. Your access has now expired. Provide feedback to your librarian. If you have any questions, please do not hesitate to reach out to our customer success team. Login processing Chapter 5: Gases. Chapter 1: Introduction: Matter and Measurement. Chapter 2: Atoms and Elements. Chapter 3: Molecules, Compounds, and Chemical Equations.
Chapter 4: Chemical Quantities and Aqueous Reactions. Chapter 6: Thermochemistry. Chapter 7: Electronic Structure of Atoms. Chapter 8: Periodic Properties of the Elements. Chapter 9: Chemical Bonding: Basic Concepts. Chapter Liquids, Solids, and Intermolecular Forces. Chapter Solutions and Colloids. Chapter Chemical Kinetics. Chapter Chemical Equilibrium. Chapter Acids and Bases. Chapter Acid-base and Solubility Equilibria. Chapter Thermodynamics.
Chapter Electrochemistry. Chapter Radioactivity and Nuclear Chemistry. Chapter Transition Metals and Coordination Complexes. Chapter Biochemistry. Full Table of Contents. This is a sample clip. Sign in or start your free trial. JoVE Core Chemistry. Previous Video. Embed Share. Ideal gases follow the relation PV over nRT equals one.
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Please enter your email address so we may send you a link to reset your password. A Use the molar mass of chlorine to calculate the amount of chlorine in the cylinder.
Then calculate the pressure of the gas using the ideal gas law. Based on the value obtained, predict whether the cylinder is likely to be safe against sudden rupture. A We begin by calculating the amount of chlorine in the cylinder using the molar mass of chlorine Using the ideal gas law and the temperature in kelvin K , we calculate the pressure:. This pressure is well within the safety limits of the cylinder.
The ideal gas law predicts a pressure 15 atm higher than that of the van der Waals equation. Liquefaction of gases is the condensation of gases into a liquid form, which is neither anticipated nor explained by the kinetic molecular theory of gases.
Both the theory and the ideal gas law predict that gases compressed to very high pressures and cooled to very low temperatures should still behave like gases, albeit cold, dense ones. As gases are compressed and cooled, however, they invariably condense to form liquids, although very low temperatures are needed to liquefy light elements such as helium for He, 4. Liquefaction can be viewed as an extreme deviation from ideal gas behavior. It occurs when the molecules of a gas are cooled to the point where they no longer possess sufficient kinetic energy to overcome intermolecular attractive forces.
The precise combination of temperature and pressure needed to liquefy a gas depends strongly on its molar mass and structure, with heavier and more complex molecules usually liquefying at higher temperatures. Conversely, small molecules with only light elements have small a coefficients, indicating weak intermolecular interactions, and they are relatively difficult to liquefy.
After a sample of air is liquefied, the mixture is warmed, and the gases are separated according to their boiling points. A large value of a in the van der Waals equation indicates the presence of relatively strong intermolecular attractive interactions.
These liquids can also be used in a specialized type of surgery called cryosurgery , which selectively destroys tissues with a minimal loss of blood by the use of extreme cold. Liquefied natural gas LNG and liquefied petroleum gas LPG are liquefied forms of hydrocarbons produced from natural gas or petroleum reserves.
It can be stored in double-walled, vacuum-insulated containers at or slightly above atmospheric pressure. LPG is typically a mixture of propane, propene, butane, and butenes and is primarily used as a fuel for home heating. At low pressure, as shown in figure b , the real gases behave more like that of the expected ideal behaviour. For gases such as CO 2 and C 2 H 4 , they deviate more than other real gases because these gases tend to liquefy at lower pressures.
Now, the graph below shows the behaviour of real gas N 2 under different temperatures. The figure shows that the real gas Nitrogen behaves more according to the ideal gas behaviour when the temperature is high. Why do gases deviate so much under high pressure and low temperature? At both the conditions, the basic assumptions that the law of the ideal gas holds, that are: the volume of the molecules of the gas are negligible and intermolecular interaction is negligible — these two become invalid.
Under low pressure, the gas molecules are farther apart from each other, and the volume of molecules is the same as the volume of the container. As the pressure increases, the molecular space contracts, and their volume becomes significant as compared to the container. If more pressure is exerted, then the gas liquefies under very high pressure such as CO 2. All the molecules attract each other by a combination of forces.
At high temperature, these have enough energy, and they overcome their attractive force and predominate by the effects of the molecular volume. On the other hand, with the decrease in the temperature, the energy of the molecules also decreases. Eventually, there comes the point where it becomes impossible for the molecules to overcome the force of attraction, and it results in the liquefaction of gas and turns into a liquid state.
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