How many moles of hydrogen gas us present in a 2.3L container at 45.6 C and has the pressure of 1.43 atm

Answer 1

Use PV = nRT with T in Kelvin (absolute temperature), making sure to pick R with the correct units.

45.6 C = 45.6 + 273 K = 318.6 K.

1.43 atm * 2.3 L = n*R*318.6 = n*0.082057366080960 (L⋅atm⋅K⁻¹⋅mol⁻¹)*318.6 and from here you can rearrange and solve for n.