Thermodynamics and Gas expansion

In summary, the question asks which row of students will be the first to experience both laughing gas and tear gas. The solution involves using the kinetic energy formula and assuming a uniform room temperature to determine the relative speeds of the molecules and their diffusion fronts.
  • #1
InfernalAsylum
1
0
Here's the Question:
In a Classroom there are 50 rows of students. A container of N20 (laughing gas) was opened at the front row and tear gas (molar mass 240 gm/mole) was opened simultaneously at the rear of the room. Which row of students will be the first to be laughing with tears in their eyes? mm(N)=14 & mm(O)=16
_______________________________
I thought I could solve it by using KE=3/2 KT and then after finding out the kinetic energy... substitute and solve for Velocity in KE=1/2 mv²
However.. in the problem it doesn't say anything about the temperature in the room so I don't know if i should assume that it's room temperature or if there's another way to solve this... Any help is appreciated.
 
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  • #2
I think it's safe to assume the temperature is uniform throughout the room. You only need the relative thermal speeds of the molecules to determine where the two "diffusion fronts" will meet.
 
  • #3


I would approach this problem by considering the principles of thermodynamics and gas expansion. First, it is important to note that both N2O and tear gas are gases at room temperature and atmospheric pressure. This means that they will behave according to the ideal gas law, which states that the pressure, volume, and temperature of an ideal gas are all directly proportional to each other.

In this scenario, the container of N2O is opened at the front row, which means that the gas will expand and fill the entire room. At the same time, the container of tear gas is opened at the rear of the room, causing it to expand and mix with the N2O gas.

Based on the ideal gas law, we can predict that the gas mixture in the room will reach a uniform temperature and pressure throughout. This means that the students in the front row, where the N2O was initially released, will experience the effects of the gas first. However, the tear gas, with its heavier molar mass, will likely take longer to reach the front of the room due to its slower diffusion rate.

Therefore, it is likely that the students in the front row will experience the effects of the N2O first, followed by the students in the second row, and so on. It is difficult to predict exactly which row will have students laughing with tears in their eyes first, as this will depend on the specific diffusion rates and concentrations of the gases in the room. However, it is safe to assume that the front rows will be affected before the rear rows.

In conclusion, the principles of thermodynamics and gas expansion suggest that the students in the front row will be the first to experience the effects of the N2O gas, while the students in the rear of the room may not experience the effects of the tear gas until it has diffused and mixed with the N2O gas.
 

What is thermodynamics?

Thermodynamics is the branch of physics that deals with the study of energy and its transformations, including heat, work, and the relationship between temperature, energy, and work.

What is gas expansion?

Gas expansion is the process by which a gas expands in volume when its temperature increases, or when the pressure on it decreases. This can be seen in everyday situations such as when a balloon is filled with air and expands as it is heated.

What is the first law of thermodynamics?

The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, but can only be transferred or converted from one form to another.

What is the second law of thermodynamics?

The second law of thermodynamics states that in any natural process, the total entropy of a closed system will always increase over time. This means that energy will always be lost in the form of heat during energy conversions.

How does thermodynamics relate to everyday life?

Thermodynamics has many practical applications in everyday life, such as in the design of engines and refrigeration systems. It also plays a role in understanding weather patterns and the behavior of materials in different temperatures and pressures.

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