Express the mass to two significant figures and include the appropriate units.

Question

Laparoscopic surgery involves inflating the abdomen with carbon dioxide gas to separate the internal organs and the abdominal wall.

If the CO2 injected into the abdomen produces a pressure of 22 mmHg and a volume of 3.95 L at 31 ∘C, how many grams of CO2 were used?

Answer 1

Find moles of CO2 and then convert to g of CO2 using the molar mass of CO2 (44 g/mol)

PV = nRT

n = PV/RT

P = pressure = 22 mm Hg x 1 atm/760 mm Hg = 0.0289 atm

V = volume = 3.95 L

R = gas constant = 0.0821 Latm/K mol

T = temperature in K = 31 + 273 = 304K

n = moles

Solve for n (moles) and convert to grams