Question

How many grams of chlorine gas (Cl2) are in a 17.8 liter sample at 1.1 atmospheres and 29°C? Show all work used to solve this problem.

Answer 1

By using the ideal-gas equation: PV = nRT

where:
P = pressure = 1.1 atm
V = volume = 17.8 L
n = number of moles Cl2 (unknown)
R = gas constant = 0.08206 L*atm/mol*K
T = temperature = 29C + 273.15 = 302.15 K
To calculate number of moles of Cl2
(1.1 atm)*(17.8 L) = n*(0.08206 L*atm/mol*K)*(302.15 K)
n = 0.79 moles Cl2

Convert moles Cl2 to grams Cl2.
Note: 1 mole Cl2 = 70.9064 grams Cl2

0.79 moles Cl2 x (70.9064 grams Cl2/1 mole Cl2) = 56.0 grams Cl2