What is the volume (in L)of 15.0 g of HBr gas at 715 torr and 90 degrees C?

Answer 1

Atomic weights: H=1 Br=80 HBr=81

15gHBr x 1molHBr/81gHBr x 22.4LHBr/1molHBr x 715torr/760torr x 363K/273K = 5.19 L

Answer 2

HBr: Mol.mass = 1 + 80 = 81g/mol.
15g ÷ 81g/mol. = 0.185 mole
0.185 x 22.4 = 4.15 Litres at STP.
STP = 273K and 760mmHg.
4.15 x 363 = V2 x 273
V2 = 1,505.8 ÷ 273 = 5.52
715mmHg ÷ 760mmHg = 0.94
Final volume (V2) = 5.52 x 0.94(pressure change)
= 5.19 Litres.