Answer: The volume occupied by 2.50 moles of 
gas at STP is 56.0L
Explanation:
According to ideal gas equation:
P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 2.50
R = gas constant =
T =temperature =
(at STP)
Thus the volume occupied by 2.50 moles of gas at STP is 56.0L
one mole of sulfuric acid will contain 2 moles of hydrogen atoms. The molar mass of sulfuric acid is 98.0795 g/mol. This means that every mole of sulfuric acid has a mass of 98.0795 g. Since you're dealing with one mole of sulfuric acid, it follows that you will also be dealing with two moles of hydrogen.
There are 5 valence electrons in a atom of phosphorus.
You would have to use the ideal gas law for this:
PV=nRT
Pressure, Volume, n=moles, R gas constant, Temperature in Kelvin
P=nRT/V
(1.8mol)(62.36)(309K)/43.0L = 805mm Hg
