Answer:
The pressure inside the vessel can be calculated using the ideal gas law, which states that:
PV = nRT
where P is the pressure, V is the volume of the vessel, n is the number of moles of gas present, R is the gas constant, and T is the temperature in Kelvin.
Since we know the volume of the vessel (5.00 L) and the temperature (25°C), we can calculate the number of moles of gas present using the ideal gas law.
First, we need to convert the volume from liters to moles:
V = nRT / P
Now, we can substitute the values we know:
V = (2.80 g N2 + 0.403 g H2 + 79.9 g He) / (22.4 L-mol/mol-K x 25°C)
where 22.4 L-mol/mol-K is the molar volume of ideal gas at STP conditions (22.4 L/mol-K at 25°C and 1 atm).
Now, we can calculate the number of moles of each gas present:
N2 = (2.80 g N2) / (28.013 g/mol) = 0.100 mol
H2 = (0.403 g H2) / (2.016 g/mol) = 0.200 mol
He = (79.9 g He) / (4.004 g/mol) = 19.98 mol
Now, we can calculate the total number of moles of gas present:
n = N2 + H2 + He
= 0.100 mol + 0.200 mol + 19.98 mol
= 20.28 mol
Now, we can calculate the pressure inside the vessel using the ideal gas law:
P = nRT / V
= (20.28 mol) x (8.314 J/mol-K) x (25°C) / (5.00 L)
= 1013.25 atm
Therefore, the pressure inside the vessel is approximately 1013.25 atm.
Step-by-step explanation: