The angle of contact at the interface of water glass is 0∘, Ethyl-alcohol glass is 0∘ Mercury glass is 140∘ and Methyl iodide is 30∘. A glass capillary is put in a trough containing one of these for liquids it is observed that the meniscus is convex. the liquid in the trough is :
The angle of contact at the interface of water glass is 0∘, Ethyl-alcohol glass is 0∘ Mercury glass is 140∘ and Methyl iodide is 30∘. A glass capillary is put in a trough containing one of these for liquids it is observed that the meniscus is convex. the liquid in the trough is :
The correct option is B Ethyl alcohol
Given ,
angle of contact (θ)=140°
Radius
of tube (r)=1mm=10⁻³m
Surface
tension (S)=0.465N/m
Density
of mercury(ρ)=13.6×10³kg/m³
Height
of liquid rise or fall due to surface tension (h)
=2Scosθ/rρg=2×0.465×cos140°/1×10⁻³×13.6×10³×9.8
=2×0.465×(−0.7660)/10⁻³×13.6×10³×9.8
=−5.34mm
Hence,
the mercury level will depressed by 5.34mm.
A glass capillary is put in a
trough containing one of these for liquids it is observed that the meniscus is
convex. the liquid in the trough is Ethyl alcohol.
Given , angle of contact (θ)=140°
Radius of tube (r)=1mm=10⁻³m
Surface tension (S)=0.465N/m
Density of mercury(ρ)=13.6×10³kg/m³
Height of liquid rise or fall due to surface tension (h)
=2Scosθ/rρg=2×0.465×cos140°/1×10⁻³×13.6×10³×9.8
=2×0.465×(−0.7660)/10⁻³×13.6×10³×9.8
=−5.34mm
Hence, the mercury level will depressed by 5.34mm.
A glass capillary is put in a trough containing one of these for liquids it is observed that the meniscus is convex. the liquid in the trough is Ethyl alcohol.
