Thermodynamics Ideal Gas Law problem (pressure problem)

In summary, to find the volume of a gas initially at STP when placed under a pressure of 5.00 atm and a temperature of 39.0°C, we use the equation (P1*V1)/(T1) = (P2*V2)/(T2), where P1 is 1 atm, V1 is 2.00 m³, T1 is 273°K, P2 is 5 atm, T2 is 312°K, and V2 is the unknown volume. By plugging in these values and solving for V2, we get a volume of .3809 m³. It is important to note that STP means the gas is at 0°C and
  • #1
Ling_Ling
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Homework Statement


If 2.00 m³ of a gas initially at STP is placed under a pressure of 5.00 atm, the temperature of the gas rises to 39.0°C. What is the volume?

STP means it's at 0°C and 1 atm of Pressure, correct?
V1 = 2.00 m³
V2 = ?
T1 = 0°C = 273°K (My main confusion was units: °C vs. °K and atm vs. Pa)
T2 = 39°C = 312°K
P1 = 1 atm = 101.3 kPa
P2 = 6 atm = 607.8 kPa
R = 8.135

Homework Equations


P1*V1 = nR*T1 (nR is a constant) (I don't think I need to use this, but this one translates into the next equation)
(P1*V1)/(T1) = (P2*V2)/(T2)

The Attempt at a Solution


101.3*2/273 = 607.8*V2/312
.742 = 1.948*V2
V2 = .3809 m³

This makes sense to me, because pressure is inversely proportional to Volume. As pressure increases, Volume decreases. Am I correct in my work and thinking?
 
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  • #2
Looks good to me. Kelvin is the correct choice of unit.
 
  • #3
You are using 6 atm. for the new pressure. It says that it is placed under a pressure of 5 atm. not an additional 5 atm. So you have to use 5 atm as the new pressure, not 6 atm. Also, you don't have to convert pressure to metric since it is just the pressure ratios you use. Other than that, as Winzer says, your method is fine.

AM
 

FAQ: Thermodynamics Ideal Gas Law problem (pressure problem)

1. What is the Ideal Gas Law and how is it related to thermodynamics?

The Ideal Gas Law is a mathematical equation that relates the pressure, volume, temperature, and amount of gas in a system. It is derived from the principles of thermodynamics, specifically the ideal gas law, which describes the behavior of gases at a molecular level.

2. How does the Ideal Gas Law help solve pressure-related problems in thermodynamics?

The Ideal Gas Law allows us to calculate the pressure of a gas based on the other variables, such as volume and temperature. It is particularly useful in thermodynamics because it helps us understand the behavior of gases in different conditions, such as changes in pressure or temperature.

3. What are the key assumptions of the Ideal Gas Law?

The Ideal Gas Law assumes that the gas particles are in constant, random motion and that they do not interact with each other. It also assumes that the gas particles have no volume and that all collisions between particles and the container walls are perfectly elastic.

4. Can the Ideal Gas Law be applied to all gases?

While the Ideal Gas Law is a useful approximation for most gases at low pressures and high temperatures, it is not always accurate for all gases. This is because some gases, such as real gases, deviate from ideal behavior due to intermolecular forces and the finite size of gas particles.

5. How can the Ideal Gas Law be used to predict changes in pressure?

The Ideal Gas Law can be rearranged to solve for pressure, which allows us to predict how changes in other variables, such as volume or temperature, will affect the pressure of a gas. This is particularly useful in thermodynamics when studying the behavior of gases in different conditions, such as during phase changes or in chemical reactions.

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