What is meant by molar volume of a gass
Answers
Answer:
The molar volume of a gas expresses the volume occupied by 1 mole of that respective gas under certain temperature and pressure conditions.
Explanation:
Answer:
The molar volume, symbol Vm, is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure. It is equal to the molar mass (M) divided by the mass density (ρ).
Explanation:
The molar volume, symbol Vm,[1] is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure. It is equal to the molar mass (M) divided by the mass density (ρ). It has the SI unit cubic metres per mole (m3/mol),[1] although it is more practical to use the units cubic decimetres per mole (dm3/mol) for gases and cubic centimetres per mole (cm3/mol) for liquids and solids.
The molar volume of a gas expresses the volume occupied by 1 mole of that respective gas under certain temperature and pressure conditions.
The most common example is the molar volume of a gas at STP (Standard Temperature and Pressure), which is equal to 22.4 L for 1 mole of any ideal gas at a temperature equal to 273.15 K and a pressure equal to 1.00 atm.
So, if you are given these values for temperature and pressure, the volume occupied by any number of moles of an ideal gas can be easily derived from knowing that 1 mole occupies 22.4 L.
V
=
n
⋅
V
m
o
l
a
r
For 2 moles of a gas at STP the volume will be
2
moles
⋅
22.4
L/mol
=
44.8
L
For 0.5 moles the volume will be
0.5
moles
⋅
22.4
L/mol
=
11.2
L
, and so on.
The molar volume of a gas is derived from the ideal gas law
P
V
=
n
R
T
:
P
V
=
n
R
T
→
V
=
n
R
T
P
→
V
n
=
R
T
P
Let's say you were given a temperature of 355 K and a pressure of 2.5 atm, and asked to determine the gas' molar volume at these conditions. Since molar volume refers to the volume occupied by 1 mole, you'd get
V
1 mole
=
0.082
L
⋅
a
t
m
m
o
l
⋅
K
⋅
355
K
2.5
a
t
m
=
11.6
L/mol
This is how much volume 1 mole occupies at 355 K and 2.5 atm. It becomes clear that the volume occupied by any number of moles at these conditions can be easily determined:
2
moles
⋅
11.6
L/mol
=
23.2
L
0.5
moles
⋅
11.6
L/mol
=
5.8
L
, and so on.
As a conclusion, knowing a gas' molar volume at a certain temperature and a certain pressure can simplify the calculation of the volume occupied by any number of moles of that respective gas
Change in volume with increasing ethanol.
The molar volume of a substance is defined as its molar mass divided by its density:
The volume of 1 mole of any gas is called its molar volume and is equal to 22.4 L at standard temperature and pressure. Molar volume allows conversions to be made between moles and volume of gases at STP. Gas density can be calculated from the molar mass and molar volume.
{\displaystyle V_{\rm {m}}={M \over \rho }}V_{\rm m} = {M\over\rho}.
If the sample is a mixture containing N components, the molar volume may be approximated as the sum of the molar volume of its individual components, using the density of the mixture.
However, many liquid–liquid mixtures, for instance mixing pure ethanol and pure water, experience contraction or expansion upon mixing. This effect is called "excess volume".