Which molecules will move faster?

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In summary, during a class discussion on the Kinetic Molecular Theory and the combined gas law, a question was posed about the movement of molecules in two balloons filled with different volumes of Helium gas. The question sparked confusion as the relationship between volume, temperature, and molecular speed was discussed. Ultimately, the KMT suggests that the molecules in both balloons would move at the same speed due to the dependence of kinetic energy on temperature, but the combined gas law suggests that the larger balloon would have a higher temperature and therefore faster-moving molecules. This contradiction has left the speaker seeking a detailed explanation.
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holydog23
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In class today, we were talking about the Kinetic Molecular Theory and the combined gas law. I was understanding everything until our teacher threw in a question that confused me really bad

Suppose we fill two balloons with Helium gas. One of them is filled 5 liters of He and the other to 10 Liters. The molecules of which balloon will move faster?

He didn't mention anything about the temperature, so I'm assuming constant temperature here because inflating balloons doesn't change temperature. Nevertheless, this question has my head spinning; a detailed explanation would be appreciated
 
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What's your head tell you?
 
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Bystander said:
What's your head tell you?
Well I postulated that the molecules in both balloons would move at the same speed; this is because according to the KMT, Kinetic Energy of gas particles is dependent only on temperature, so they should be at the same speed. But because of Gay-lussac's law, Volume is directly proportional to temperature, so if the volume increases, the temperature should increase and thus make the molecules within the 10 L faster. But this contradicts the KMT since it states that KE of these molecules is dependent ONLY on temperature
 
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PV = RT, or PV = nRT?
 

1. What determines the speed of molecules?

The speed of molecules is determined by their mass, temperature, and the medium they are moving through. Generally, smaller and lighter molecules will move faster than larger and heavier molecules. Higher temperatures also increase the speed of molecules, as they have more energy to move and collide with each other. In addition, the viscosity of the medium can affect molecule speed, with less viscous mediums allowing for faster movement.

2. Do all molecules move at the same speed?

No, all molecules do not move at the same speed. As mentioned, the speed of molecules is influenced by various factors such as mass, temperature, and medium, so different molecules will have different speeds. However, within a specific substance or environment, the molecules will have a range of speeds rather than all moving at the same speed.

3. Can we predict which molecules will move faster?

Yes, we can make predictions about which molecules will move faster based on their characteristics and the conditions they are in. For example, smaller and lighter molecules will generally move faster than larger and heavier molecules, and molecules in higher temperatures will move faster than those in lower temperatures. However, the exact speed of a molecule cannot be predicted with complete accuracy due to the random motion of molecules.

4. How does molecular speed affect chemical reactions?

The speed of molecules can greatly impact the rate of chemical reactions. Faster-moving molecules have more energy and are more likely to collide with each other, leading to more frequent and successful reactions. Additionally, higher molecular speeds can also overcome activation energy barriers, allowing for reactions to occur more quickly.

5. Does the shape of a molecule affect its speed?

Yes, the shape of a molecule can affect its speed. Molecules with more compact and streamlined shapes tend to have higher speeds, as they experience less resistance from the surrounding medium. On the other hand, molecules with more complex and irregular shapes may have lower speeds due to increased resistance and collisions with other molecules.

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