Textbook Question
Consider the following gases, all at STP: Ne, SF6, N2, CH4. (d) Which one has the highest total molecular volume relative to the space occupied by the gas?
Ch.10 - Gases
Chapter 10, Problem 114
Does the effect of intermolecular attraction on the properties of a gas become more significant or less significant if the gas is compressed to a smaller volume at constant temperature?
Verified step by step guidance1
Step 1: Understand the concept of intermolecular forces. These are forces of attraction or repulsion between neighboring particles (atoms, molecules, or ions). In gases, these forces are generally weak due to the large distances between particles.
Step 2: Recall the ideal gas law, PV = nRT, which assumes that there are no intermolecular forces and that the volume of the gas particles is negligible. This is a good approximation under conditions of low pressure and high temperature.
Step 3: Consider what happens when a gas is compressed to a smaller volume at constant temperature. The particles are forced closer together, which increases the significance of intermolecular forces because the particles are now closer and can interact more strongly.
Step 4: Recognize that as the volume decreases, the gas deviates from ideal behavior. The attractive forces between particles become more significant, affecting properties such as pressure and volume.
Step 5: Conclude that the effect of intermolecular attraction on the properties of a gas becomes more significant when the gas is compressed to a smaller volume at constant temperature, leading to deviations from ideal gas behavior.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Intermolecular Forces
Intermolecular forces are the attractive forces between molecules that influence the physical properties of substances. In gases, these forces are generally weak compared to those in liquids and solids, allowing gas molecules to move freely. However, when a gas is compressed, the proximity of the molecules increases, enhancing the effect of these forces on the gas's behavior.
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Intermolecular vs Intramolecular Forces
Ideal Gas Law
The Ideal Gas Law, represented as PV=nRT, describes the relationship between pressure (P), volume (V), temperature (T), and the number of moles (n) of a gas. It assumes that gas molecules do not interact with each other, which is a valid approximation at low pressures and high temperatures. However, deviations from ideal behavior occur when gases are compressed, as intermolecular attractions become more significant.
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Compressibility and Real Gases
Compressibility refers to the ability of a substance to decrease in volume under pressure. Real gases deviate from ideal behavior at high pressures and low temperatures, where intermolecular attractions become significant. When a gas is compressed, these attractions can lead to a decrease in pressure compared to what the Ideal Gas Law would predict, indicating that intermolecular forces play a more critical role in the gas's properties.
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Related Practice
Textbook Question
Consider the following gases, all at STP: Ne, SF6, N2, CH4. (f) Which one would effuse more rapidly than N2?
Textbook Question
Consider the following gases, all at STP: Ne, SF6, N2, CH4. (g) Which one would have the largest van der Waals b parameter?
Textbook Question
It turns out that the van der Waals constant b equals four times the total volume actually occupied by the molecules of a mole of gas. Using this figure, calculate the fraction of the volume in a container actually occupied by Ar atoms (b) at 20.27 MPa pressure and 0 °C. (Assume for simplicity that the ideal-gas equation still holds.)
Textbook Question
Large amounts of nitrogen gas are used in the manufacture of ammonia, principally for use in fertilizers. Suppose 120.00 kg of N2(g) is stored in a 1100.0-L metal cylinder at 280 °C. (b) By using the data in Table 10.3, calculate the pressure of the gas according to the van der Waals equation.