Answer:
Molar mass = 105 g/mol
Explanation:
Given data:
Mass of gas = 3.15 g
Pressure = 785 mmHg
Temperature = 20°C
Volume of gas = 750 mL
Molar mass of gas = ?
Solution:
Pressure = 785 mmHg (785/760 = 1 atm)
Temperature = 20°C (20+273 = 293 K)
Volume of gas = 750 mL (750 mL× 1 L/1000 mL = 0.75 L)
PV = nRT
R = general gas constant (0.0821 atm.L/mol.K)
1 atm× 0.75 L = n×0.0821 atm.L/mol.K × 293 K)
0.75 atm.L = n× 24.06 atm.L/mol
n = 0.75 atm.L / 24.06 atm.L/mol
n = 0.03 mol
Molar mass of gas:
Molar mass = Mass / number of moles
Molar mass = 3.15 g/ 0.03 mol
Molar mass = 105 g/mol
