How Does a Rising Bubble's Volume Change with Pressure and Temperature?

In summary, the ratio of the volume of the bubble as it reaches the surface to its volume at the bottom is 20.125. If the temperature was given in Fahrenheit, it would be converted to Kelvin before solving the problem. As for the safety of the diver holding his breath while ascending, it would still not be safe as the volume of air still expands significantly. Another difference between a diver and a bubble is that the diver's lungs can expand to accommodate the expanding air.
  • #1
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Homework Statement


A diver observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm to the surface (where the pressure is 1.00 atm). The temperature at the bottom is 4.0 C, and the temperature at the surface is 23.0 C}.

What is the ratio of the volume of the bubble as it reaches the surface to its volume at the bottom, V2/V1?


Homework Equations


p1V1/T1 = p2V2/T2

V2/V1 = p1/p2 * T2/T1

The Attempt at a Solution



V2/V1 = (3.5)/1 * 23/4

V2/V1 = 20.125
 
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  • #2
How would you solve the problem if the temperature was given to you in Fahrenheit?
 
  • #3
I would convert to K. That gave me the correct answer. Thanks!

Also, there's a second part to this question:

"Would it be safe for the diver to hold his breath while ascending from the bottom of the lake to the surface?"

My first answer would be no, because the solution V2/V1 = 3.74 shows that the volume of air expands more than three times, but I think that the temperature inside the diver should stay the same, and so it won't expand like this. What's the answer?
 
Last edited:
  • #4
Well, you could assume that the temperature doesn't change from the bottom to the top - you will still get a factor of more than three. What other difference is there between a diver and a bubble? :smile:
 

1. What is the ideal gas equation?

The ideal gas equation, also known as the ideal gas law, is a mathematical equation that relates the pressure, volume, temperature, and number of moles of an ideal gas. It is written as PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.

2. When can the ideal gas equation be used?

The ideal gas equation can be used to calculate the properties of an ideal gas under standard conditions (0°C and 1 atm) or in cases where the gas behaves as an ideal gas, such as at low pressures and high temperatures. It is not suitable for real gases, which have non-ideal behavior at high pressures and low temperatures.

3. How do you solve ideal gas equation problems?

To solve an ideal gas equation problem, you need to know three of the four variables (pressure, volume, temperature, and number of moles) and use the equation PV = nRT to calculate the unknown variable. You may need to convert units to ensure that all variables are in the correct units (pressure in atm, volume in liters, temperature in Kelvin, and number of moles in moles).

4. What are the units of the ideal gas constant (R)?

The ideal gas constant has different units depending on the units used for pressure, volume, temperature, and number of moles. In SI units, R = 8.314 J/mol·K, but it can also be expressed in other units, such as L·atm/mol·K or cm^3·bar/mol·K. It is important to use the correct units for the given problem to get an accurate result.

5. How does the ideal gas equation relate to the kinetic molecular theory of gases?

The ideal gas equation is based on the assumptions of the kinetic molecular theory of gases, which states that gases are made up of tiny particles in constant motion and that the pressure exerted by a gas is due to collisions between these particles and the walls of the container. The ideal gas equation incorporates these assumptions by relating the pressure (P) to the average kinetic energy of the particles (nRT/V).

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