Respuesta :
Answer:
The molar mass of the compound is:- 168.82 g/mol
The molar mass of the gas is:- 16.38 g/mol
Explanation:
(a)
Using ideal gas equation as:
[tex]PV=nRT[/tex]
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Also,
Moles = mass (m) / Molar mass (M)
Density (d) = Mass (m) / Volume (V)
So, the ideal gas equation can be written as:
[tex]PM=dRt[/tex]
Given that:-
Pressure = 20 kPa = 20000 Pa
The expression for the conversion of pressure in Pascal to pressure in atm is shown below:
P (Pa) = [tex]\frac {1}{101325}[/tex] P (atm)
20000 Pa = [tex]\frac {20000}{101325}[/tex] atm
Pressure = 0.1974 atm
Temperature = 330 K
d = 1.23 kg/m³ = 1.23 g/L
Molar mass = ?
Applying the equation as:
0.1974 atm × M = 1.23 g/L × 0.0821 L.atm/K.mol × 330 K
⇒M = 168.82 g/mol
The molar mass of the compound is:- 168.82 g/mol
(b)
Given that:
Pressure = 152 Torr
Temperature = 298 K
Volume = 250 cm³ = 0.25 L
Using ideal gas equation as:
[tex]PV=nRT[/tex]
R = [tex]62.3637\text{torr}mol^{-1}K^{-1}[/tex]
Applying the equation as:
152 Torr × 0.25 L = n × 62.3637 L.torr/K.mol × 298 K
⇒n = 0.002045 moles
Given that :
Mass of the gas = 33.5 mg = 0.0335 g
Molar mass = ?
The formula for the calculation of moles is shown below:
[tex]moles = \frac{Mass\ taken}{Molar\ mass}[/tex]
Thus,
[tex]0.002045\ moles = \frac{0.0335\ g}{Molar\ mass}[/tex]
The molar mass of the gas is:- 16.38 g/mol
