Chapter 12.1, Problem 11SSC

Interpretation Introduction

Interpretation:

The reason of inversion of container of water when a gas is collected by displacement of water needs to be explained.

Concept introduction:

Gas is one of the physical states of matter in which the particles are located away from each other.

The particles of gas have high kinetic energy and exhibit different characteristics compare to liquid and solids.

Answer to Problem 11SSC

During the collection of gas in any method, the inverted container of water is used. This is because the water level in the container adjusts the pressure inside and outside. It helps to calculate the pressure of gas with the comparison of atmospheric pressure.

Explanation of Solution

Due to high kinetic energy and elastic collisions of gas particles with the container wall, they exert certain pressure on the wall of container. This is called as gas pressure. The gas pressure can measure with the help of various devices such as manometer or barometer. During the collection of gas in any method, the inverted container of water is used. This is because the water level in the container adjust the pressure inside and outside. It helps to calculate the pressure of gas with the comparison of atmospheric pressure. Thus:

${\text{P}}_{\text{T}}{\text{ = P}}_{\text{gas}}{\text{ + P}}_{\text{H}}{{}_{{}_{\text{2}}}}_{\text{O}}$

Here total pressure is the atmospheric pressure, which must be sum of pressure of gas and water.

Conclusion

Thus,

${\text{P}}_{\text{T}}{\text{ = P}}_{\text{gas}}{\text{ + P}}_{\text{H}}{{}_{{}_{\text{2}}}}_{\text{O}}$