<h3>
Answer: 386.67 g/mol </h3>
Explanation:
Molar Mass = Mass ÷ Mole
= 0.406 g ÷ 0.00105 mol
= 386.67 g/mol
∴ molar mass of cholesterol = 386.67 g/mol
Answer:
d = 0.9 g/L
Explanation:
Given data:
Number of moles = 1 mol
Volume = 24.2 L
Temperature = 298 K
Pressure = 101.3 Kpa (101.3/101 = 1 atm)
Density of sample = ?
Solution:
PV = nRT (1)
n = number of moles
number of moles = mass/molar mass
n = m/M
Now we will put the n= m/M in equation 1.
PV = m/M RT (2)
d = m/v
PM = m/v RT ( by rearranging the equation 2)
PM = dRT
d = PM/RT
The molar mass of neon is = 20.1798 g/mol
d = 1 atm × 20.1798 g/mol / 0.0821 atm. L/mol.K × 273K
d = 20.1798 g/22.413 L
d = 0.9 g/L
Difference between Gas and Vapour:
Gas:
A thermodynamic state in which a substance exists only in one phase i.e. Gas phase. In above given examples N₂, He and CO₂ exists as gases at room temperature. These gases cannot form a solid or liquid phase along with gas phase as these states requires very low temperatures.
Vapours:
It is a thermodyanamic state in which a substance exists in more than one phase. In given options Sulfur can exist in vapor state. This is because sulfur exists in a cyclic or chain form due to catenation (self linkage property). Therefore, a lower members of S allotrops can form a vapours.
<span>An example of sublimation is when a dry ice changes to carbon dioxide when kept in an open container. Sublimation is a change from solid phase to gas phase without passing through the liquid state. In this example, it is clear that the dry ice is solid form and it evaporates as gas without passing through the liquid state.</span>
