A gas occupies a volume of exactly 500mL at STP. What would it occupy at exactly 70 degrees celsius and 400 mm of pressure?
(P1V1/T1) = (P2V2/T2)
To determine the volume of the gas at a different temperature and pressure, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure
V = volume
n = number of moles of gas
R = ideal gas constant
T = temperature
At STP (Standard Temperature and Pressure), the values are defined as 0 degrees Celsius (273.15 Kelvin) and 1 atmosphere of pressure (760 mmHg or 101.3 kPa or 1013.25 hPa).
To find the volume at a different temperature and pressure, we can follow these steps:
1. Convert the provided temperature to Kelvin. To convert Celsius to Kelvin, simply add 273.15 to the Celsius temperature.
Temperature in Kelvin = 70 degrees Celsius + 273.15 = 343.15 K
2. Convert the provided pressure from mm of Hg to atm. Divide the pressure in mmHg by 760 to get the pressure in atmospheres.
Pressure in atmospheres = 400 mmHg / 760 = 0.526 atm
3. Plug the values into the ideal gas law equation rearranged to solve for V (volume):
V = nRT / P
Since we don't have information about the number of moles, we can assume it remains constant. Therefore, we can rewrite the equation as:
V1 / P1 = V2 / P2
Substituting the values:
500 mL / (1 atm) = V2 / (0.526 atm)
4. Solve for V2, the volume at the provided temperature and pressure:
V2 = (500 mL)(0.526 atm) / (1 atm)
V2 = 263 mL
Therefore, the gas would occupy a volume of 263 mL at exactly 70 degrees Celsius and 400 mmHg pressure.