Answer: 41 atmosphere
Explanation:
Given that:
Volume of water V = 0.5 L
(since 1 liter = 1dm3
0.5L = 0.5dm3)
Temperature T = 500K
Pressure P = ?
Number of moles of gas = 5 moles
Note that Molar gas constant R is a constant with a value of 0.0082 ATM dm3 K-1 mol-1
Then, apply ideal gas equation
pV = nRT
p x 0.5dm3 = 5 moles x (0.0082 atm dm3 K-1 mol-1 x 500K)
p x 0.5dm3 = 20.5 atm dm3
p = (20.5 atm dm3 / 0.5dm3)
p = 41 atm
Thus, the gas is under a pressure of 41 atmosphere