Final answer:
To find the volume that 5.00 g of helium gas will occupy at 0.800 atmospheres and 25°C, convert the mass of helium to moles, convert Celsius to Kelvin, and use the Ideal Gas Law. The calculation reveals that the volume will be approximately 38.3 liters.
Step-by-step explanation:
To determine the volume occupied by 5.00 g of helium gas at 0.800 atmospheres and 25℃, we can use the Ideal Gas Law: PV = nRT, where P is pressure, V is volume, n is number of moles, R is the universal gas constant, and T is temperature.
First, we need to convert the mass of helium to moles by using molar mass: The molar mass of helium is about 4.00 g/mol, thus:
n = mass / molar mass = 5.00 g / 4.00 g/mol = 1.25 moles.
Next, we convert the temperature to Kelvin: T(K) = 25℃ + 273.15 = 298.15 K.
Using the Ideal Gas Law and solving for V:
V = (nRT) / P
V = (1.25 moles * 0.0821 L atm mol⁻¹ K⁻¹ * 298.15 K) / 0.800 atm
V = approximately 38.3 L
Therefore, 5.00 g of helium gas will occupy approximately 38.3 liters at 0.800 atmospheres and 25℃.