Question

If a cylinder contains 41.8 g of CO2 in 29.5 L at 455. K, what is the pressure (in mmHg)? Be sure your answer has the correct number of significant figures.

Note: Reference the Fundamental constants and Conversion factors for non-SI units tables for additional information.


what is the answer

Answer 1

To find the pressure of the CO2 gas in the cylinder, we can use the ideal gas law equation:

PV = nRT

Where:
P = pressure
V = volume in liters
n = moles of gas
R = ideal gas constant (0.0821 L.atm/mol.K)
T = temperature in Kelvin

First, we need to find the moles of CO2 using the given mass:

molar mass of CO2 = 12.01 g/mol (C) + 2(16.00 g/mol) = 44.01 g/mol

moles of CO2 = mass / molar mass
moles of CO2 = 41.8 g / 44.01 g/mol
moles of CO2 = 0.950 mol

Now, we can plug in the values into the ideal gas law:

P(29.5 L) = (0.950 mol)(0.0821 L.atm/mol.K)(455 K)

P(29.5) = 36.994 atm

P = 36.994 atm / 29.5
P = 1.2545 atm

Since we need to convert the pressure to mmHg, we can use the conversion factor:

1 atm = 760 mmHg

P = 1.2545 atm * 760 mmHg/atm
P = 953 mmHg

Therefore, the pressure of the CO2 gas in the cylinder is 953 mmHg with the correct number of significant figures.