please help chemistry

Question

what is the density (g/L) of hydrogen gas at 20.0 c and a pressure of 1655 psi?

Answer 1

PV = nRT (Ideal gas law)

P = pressure = 1655 psi. Convert 1655 psi to atm: 1 atm = 14.7 psi

P = 1655 psi x 1 atm / 14.7 psi = 112.6 atm

V = volume in L = 1 L (we can choose any volume we wish & we want g / L so choose 1 L)

n = moles of H2 = ?

R = gas constant = 0.0821 Latm/Kmol

T = temperature in K = 20.0C + 273 = 293K

Solving for n (moles of H2), we have ...

n = PV/RT = (112.6 atm)(1 L) / (0.0821 Latm/Kmol)(293K)

n = 4.681 moles of H2

mass H2 = 4.681 mols x 2.02 g/mol = 9.46 g of H2

density = g/L = 9.46 g / L

(be sure to check the math)