A sample of gas collected at 25 degree Celsius and 2 atm pressures occupies 500 mL. What volume would it occupy at STP?

To find the volume of the gas at STP (Standard Temperature and Pressure), we need to use the ideal gas law equation:

PV = nRT

Where:
P = pressure
V = volume
n = number of moles
R = ideal gas constant
T = temperature

At 25 degrees Celsius, the temperature is 298 K (25 + 273). The pressure is 2 atm.

Now, we can rearrange the equation to solve for the volume at STP:

V1/T1 = V2/T2

(2 atm)(500 mL) / 298 K = (1 atm)(V2) / 273 K

V2 = (2 atm)(500 mL)(273 K) / (1 atm)(298 K)
V2 = 364.43 mL

Therefore, the gas would occupy 364.43 mL at STP.