Answer:
MOLAR MASS = 32 g/mol
Explanation:
Condition of standard temperature and pressure(STP) are as follow:
Temperature = 273 K
Pressure = 1 atm (or 100000 Pa)
Here atm is atmosphere and Pa is Pascal
STP conditions arte used for measuring gas density and volume using Ideal Gas Law.Here 1 mole of ideal gas occupies 22.4 L of volume.
According toi Ideal Gas Equation :
PV = nRT
where P = pressure, n= number of moles, V = volume ,R= Ideal Gas Constant and T= temperature
[tex]n=\frac{PV}{RT}[/tex]
From question:
V=280 ml = 0.28 L
P = 1 atm
R=0.08205 L atm/K mol
T=273 K
Putting values in above formula :
[tex]n=\frac{1\times .280}{0.08205\times 273}[/tex]
n = 0.0125 moles
Now [tex]n=\frac{given\ mass}{Molar\ mass}[/tex]
[tex]Molar\ mass=\frac{given\ mass}{n}[/tex]
given mass = 0.4 g (given)
[tex] Molar\ mass=\frac{0.4}{0.0125}[/tex]
On solving we get:
Molar mass = 32 g/mol
