The volume of 0.2 moles of helium at STP (Standard Temperature and Pressure) is 4.48 liters, calculated by multiplying the number of moles by the molar volume of a gas at STP, which is 22.4 L/mole.
The volume of a gas at STP (Standard Temperature and Pressure) can be determined using the ideal gas law, which states that one mole of any gas at STP occupies 22.4 liters.
Since you have 0.2 moles of helium, you can calculate the volume by multiplying the number of moles by the molar volume at STP.
To calculate the volume of 0.2 moles of helium at STP:
Identify that at STP, 1 mole of gas occupies 22.4 L.
Multiply the volume occupied by 1 mole by the number of moles you have (0.2 moles).
Volume = Number of moles × Molar volume at STP
Volume = 0.2 moles × 22.4 L/mole
Volume = 4.48 L
Therefore, the volume of 0.2 moles of helium gas at STP is 4.48 liters.