Final answer:
Using the Ideal Gas Law and converting the mass of each gas to moles, we can find that the pressure in the cylinder is approximately 20.6 atmospheres, corresponding to choice option (c) 20.6 atm.
Step-by-step explanation:
To calculate the pressure in the cylinder at 25 degrees Celsius, we can use the Ideal Gas Law, which is PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the gas constant, and T is the temperature in Kelvin.
First, we need to determine the number of moles of each gas. We do this by dividing the mass of each gas by its molar mass (44.01 g/mol for CO₂, 32.00 g/mol for O₂, and 28.02 g/mol for N₂). Then we add these moles together to get the total moles of gas.
Next, we convert the temperature from Celsius to Kelvin by adding 273 to the Celsius temperature. Now we can plug in our values into the Ideal Gas Law equation and solve for P. The gas constant R when using atmospheres for pressure and liters for volume is 0.0821 L*atm/mol*K.
After performing the calculations, we find that the pressure in the cylinder is approximately 20.6 atmospheres. So, the answer to the question is (c) 20.6 atm.