CBSE Class 11-science Answered
If we have a sample of water in a closed container, some of the water will evaporate until pressure of the water vapour at 22°C is 19.8 mm Hg. How many molecules of water per cubic centimeters exist in the vapour phase?
Asked by amangeneralstore27 | 21 Dec, 2019, 11:03: AM
Expert Answer
Let us use ideal gas equation, p V = n R T .............(1)
where p is pressure, p = ρgh ,
ρ is density of mercry, g is acceleration due to gravity and h is height of mercury column
p = 13590 × 9.8 × 19.8 × 10-3 = 2637 Pa
V is volume , V = 1 cm3 = 10-6 m3
n is number of moles, R is universal gas constant, R = 8.314 J / mole /K
T is temperature in Kelvin
hence number of moles in 1 cm3 water vapour is given by,
n = ( p V ) / ( R T ) = 2637 × 10-6 / ( 8.314 × 295) = 1.075 × 10-6
Number of molecules in 1 cm3 water vapour is obtained by multiplying number of moles by Avagadro number
Number of molecules in 1 cm3 water vapour = 1.075 × 10-6 × 6.022 × 1023 = 6.475 × 1017
Answered by Thiyagarajan K | 23 Dec, 2019, 08:13: PM
CBSE 11-science - Physics
Asked by sumedhasingh238 | 28 Mar, 2024, 11:10: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by roshnibudhrani88 | 23 Mar, 2024, 05:52: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by emad.amd | 21 Mar, 2024, 12:00: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by vinitdubey7735 | 14 Mar, 2024, 11:21: AM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by om636694 | 04 Mar, 2024, 09:10: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rajuinwati12 | 04 Mar, 2024, 09:22: AM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rosysahu678 | 02 Mar, 2024, 06:09: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by vaddevenkatesulu56 | 26 Feb, 2024, 09:02: PM
ANSWERED BY EXPERT
CBSE 11-science - Physics
Asked by rustampathan | 25 Feb, 2024, 06:39: PM
ANSWERED BY EXPERT