Answer:
79.89 g/mol
Explanation:
The following data were obtained from the question:
Mass (m) of gas = 0.6 g
Volume (V) = 211 mL
Temperature (T) = 24 °C
Pressure (P) = 660 mmHg
Molar mass of gas =.?
Next, we convert 24 °C to Kelvin temperature. This can be obtained as follow:
Temperature (K) = temperature (°C) + 273
Temperature (°C ) = 24 °C
Temperature (K) = 24 + 273 = 297 K
Next, we shall convert 211 mL to litres (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
211 mL = 211 mL × 1 L / 1000 mL
211 mL = 0.211 L
Next, we shall convert 660 mmHg to atm. This can be obtained as follow:
760 mmHg = 1 atm
Therefore,
660 mmHg = 660 mmHg × 1 atm / 760 mmHg
660 mmHg = 0.868 atm
Next, we shall determine the number of mole of the gas. This can be obtained as shown below:
Volume (V) = 0.211 L
Temperature (T) = 297 K
Pressure (P) = 0.868 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Number of mole (n) =?
PV = nRT
0.868 × 0.211 = n × 0.0821 × 297
Divide both side by 0.0821 × 297
n = (0.868 × 0.211) / (0.0821 × 297)
n = 7.51×10¯³ mole.
Finally, we shall determine the molar mass of the gas as shown below:
Mass of gas = 0.6 g
Number of mole of gas = 7.51×10¯³ mole.
Molar mass of gas =.?
Mole = mass /Molar mass
7.51×10¯³ = 0.6 / Molar mass
Cross multiply
7.51×10¯³ × molar mass = 0.6
Divide both side by 7.51×10¯³
Molar mass = 0.6 / 7.51×10¯³
Molar mass of gas = 79.89 g/mol
