Final answer:
Using Dalton's law of partial pressures, the partial pressure of argon in a container with 30% helium by volume and a total pressure of 4.00 atm is calculated to be 2.80 atm.
Step-by-step explanation:
To calculate the partial pressure of argon in a container where helium occupies 30.0% by volume, we'll use Dalton's law of partial pressures.
This law states that the total pressure inside a container is the sum of the partial pressures of the individual gases inside the container.
Given the total pressure is 4.00 atm and helium makes up 30.0% by volume, we can calculate the volume percentage of argon as 100% - 30% = 70%.
Because the gases are in the same container, we can assume their partial pressures are proportional to their volume percentages.
The partial pressure of argon can be found using the formula:
Partial pressure of argon = Total pressure × (Volume % of argon / 100%)
Substituting the known values:
Partial pressure of argon = 4.00 atm × (70% / 100%)
Partial pressure of argon = 4.00 atm × 0.70
Partial pressure of argon = 2.80 atm
Therefore, the partial pressure of argon in the container is 2.80 atm.