# Where Did I Go Wrong in My Gas Law Calculation?

• Chemistry
• aboredperson
aboredperson
Homework Statement
Given three rigid 1.00-Liter containers at 25o C filled with 1.00 mole of helium gas, 2.00 moles of neon gas, and 3.00 moles of argon gas respectively. When all three gases are pumped into a fourth 1.00-Liter container, what is the volume occupied by the neon gas in the final mixture?
a) 1.00L b) 2.00L c) 3.00L d) 0.167L. E) 0.333L
Relevant Equations
PV=nRT
P=pressure(atm) V= volume (L) n= Moles R= 0.0821 T= Temperature(K)
PV=nRT
P*1L = 6 moles * 0.0821*298 (I added up all the moles and solved for pressure)
P =146.79 atm
146.79 atm * V = 2 moles Ar * 0.0821* 298 (I plugged in the moles for argon and solved for volume)
V= 0.333 L
Answer key says the answer is 1 Liter. Where did I go wrong?

Looks like you have assumed that partial pressure of the neon gas is the same as the total pressure in the mixture.

Last edited:
The 3 gases don't occupy distinct portions of the receiving container separately. They all occupy the complete receiving container. Each gas in an ideal gas mixture behaves as if the other gases are not even present.

## 1. Did I use the correct units for pressure, volume, and temperature?

It's crucial to ensure that all units are consistent with the gas law equation you are using. Commonly, pressure should be in atmospheres (atm), volume in liters (L), and temperature in Kelvin (K). Converting units incorrectly can lead to significant errors.

## 2. Did I convert the temperature to Kelvin?

Gas law calculations require temperature to be in Kelvin. If you used Celsius or Fahrenheit, the results will be incorrect. To convert Celsius to Kelvin, add 273.15 to the Celsius temperature.

## 3. Did I account for the number of moles of gas correctly?

Ensure that the number of moles (n) is accurately calculated or given. Errors in determining the amount of substance can lead to incorrect results in calculations involving the Ideal Gas Law (PV=nRT).

## 4. Did I use the correct value for the gas constant (R)?

The gas constant (R) has different values depending on the units used for pressure, volume, and temperature. For example, R = 0.0821 L·atm/(K·mol) when using liters for volume and atmospheres for pressure. Using the wrong value for R can cause errors in your calculations.

## 5. Did I correctly apply the ideal gas law or the appropriate gas law for the conditions?

Make sure you are using the correct gas law for the situation. The Ideal Gas Law (PV=nRT) is a good approximation for many conditions, but for high pressures, low temperatures, or real gases, you might need to use the Van der Waals equation or another real gas model.

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