Gas - Practice Questions & MCQ

The Gaseous State
Gases and their properties play an important role in our daily lives. Our atmosphere consists Of mixture Of gases like dioxygen, dinitrogen, carbon dioxide, water vapours etc. These gases shield us from harmful radiations. Life is supported by the dioxygen in the air which we breathe. Plants need carbon dioxide for photosynthesis. 
There are in total eleven elements in the periodic table which exist as gases under normal conditions.

Composition of gases is always from non-metal eg. etc.

Following are the few physical properties of gaseous state : 

(i) The volume and shape of gases is not fixed. These assume the volume and shape of the container. 

(ii) The thermal energy of gases >> molecular attraction. 

(iii) Gases have infinite expansibility and high compressibility. 

(iv) Gases exert pressure equally in all directions 

(v) Gases have much lower density than the solids and liquids due to negligible intermolecular forces. 

vi) Gas mix evenly with other gases or their mixtures are homogeneous in composition.

Characteristics of Gas 

There are certain parameters or measurable properties which are used to describe the characteristics of gases 

• Volume (V): The volume of the container is the volume of the gas sample as gases occupy the entire space available to them.
  
   
• Pressure (P): Pressure Of the gas is the force exerted by the gas per unit area on the walls of the container in all directions.
  
   
• Temperature: It is the measure of hotness of the system and energy of the system.
  
   
• Mass: The mass of a gas can be determined by weighing the container in which the gas is enclosed and again weighing the container after removing the gas. The mass of the gas is related to the number of moles of the gas i.e.