What volume does 8.0g of carbon dioxide gas occupy at STP

Answer 1

First determine the number of moles that are in 8.0 grams. To do that use the molar mass. To get the molar mass, write the chemical formula for carbon dioxide (which is CO₂). Look up the atomic masses of the components on the periodic table and add them up:

C (carbon) = 12.011

O (oxygen) = 15.999 but there are two atoms so 15.999(2) = 31.998

12.011 + 31.998 = 44.009 g/mole

(8.0 g)/(44.009 g/mole) = 0.18178 moles

STP means T = 0°C or 273.15 K and pressure ≈ 1 atm.

The Ideal Gas Law is PV = nRT where we can look up the value of "R" in a reference book as 0.08206 L-atm/(mole-K). Using this value, P will be pressure in atm, V will be volume in liters, n will be the number of moles, and T will be the temperature in K:

PV = nRT

(1)V = (0.18178)(0.08206)(273.15)

V = 4.1 L