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Kinetic Theory — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysicsKinetic Theory4 Marks
Question
$50cc$ of oxygen is collected in an inverted gas jar over water. The atmospheric pressure is $99.4kPa$ and the room temperature is $27°C$. The water level in the jar is same as the level outside. The saturation vapour pressure at $27°C$ is $3.4kPa$. Calculate the number of moles of oxygen collected in the jar.
✓

Answer


Pressure inside the tube = Atmospheric Pressure = 99.4KPa
Pressure exerted by $O_2$ vapour = Atmospheric pressure - V.P.
$= 99.4KPa - 3.4KPa = 96KPa$
No of moles of $O_2 = n$
$96\times10^3\times50\times10^{-6}=\text{n}\times8.3\times300$
$\Rightarrow\text{n}=\frac{96\times50\times10^{-3}}{8.3\times300}=1.9277\times10^{-3}\approx1.93\times10^{-3}$

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