At a pressure of 770 mm Hg, a fixed mass of hydrogen gas occupies a volume of 75cm at 27°C. What volume will the mass of hydrogen gas occupy at that temperature and 750 mmHg pressure? [2]
OR
What will be the volume of 64 g of O2 gas (O=16) at a pressure of 2 atmospheres and temperature of 300K? [2]
(R = 0.082 litre – atmosphere mol-1K-1)
Initial pressure (P1) = 770 mm Hg
Initial volume (V1) = 75 cm3
Final pressure (P2) = 750 mm Hg
Final volume (V2) =?
Apply Boyle’s Law:
P1V1 = P2V2
Or, V2 = P_1V_1\over P_2
or, V2 = 770 × 75\over 750 = 77 cm3
The volume of hydrogen gas at 750 mm Hg pressure will be 77 cm3.
OR
Mass of O2 = 64 g
Pressure (P) = 2 atm
Temperature (T) = 300 K
R = 0.082 L·atm·mol⁻¹·K⁻¹
Molar mass of O₂ (O = 16) = 32 g
mole (n) = mass\ of\ O_2\over molar\ mass\ of\ O_2 = 2
The ideal gas law is: PV = nRT
V = nRT\over P
V = 2 × 0.082 × 300\over 2
V = 2 × 0.082 × 300\over 2 = 24.6
The volume of 64 g of O₂ gas at 2 atm and 300 K is 24.6 litres.
Related Questions
More WBBSE Moderate level questions