Question

To find the volume of a flask, it is first evacuated so it contains no gas. Next, 3.3 g CO₂ is introduced into the flask. On warming to 30 °C, the gas exerts a pressure of 810.0 mm Hg. What is the volume of the flask in milliliters?

Answer 1

PV = nRT

where:

P is the pressure of the gas = 810.mm hg = 1.06579 atm

V is the volume of the gas = ?

n is the amount of substance of gas (in moles) = 3.3 / 44 = 0.075 mol

R is gas constant = = 0.0821 L atm K-1 Mol-1

T is the absolute temperature of the gas = 273 + 30 = 303

substitute in the equation and calculate volume

Volume = 0.075 mol x 0.0821 L atm K-1 Mol-1 x 303 K / 1.06579 atm   = 1.75 Liter

Hence volume of the flask = 1.75 Liter = 1750 ml