An inert gas is a gas that is not able to react with substances or absorb and/or release energy. The gas is typically colourless, odourless, tasteless, has no surface tension, is not flammable, and has no reactivity with substances. Inert gas is a general term that describes gases that have the above characteristics and are considered non-reactive. Inert gases do not react with substances, but they are capable of reacting with substances at high temperatures and pressure. The addition of a slight amount of inert gas to a solution can have a very important effect on its properties and can lead to new and unexpected phenomena.

Uses of Addition of an Inert Gas 

Inert gases are used to hold down the pressure within the laboratory, replace the oxygen in the air, make the reaction run faster, for more accurate measurements, slow air down or compress it, and improve fuel efficiency for aeroplanes. The inert gas also helps to maintain a constant proportion of gases. The addition of inert gases (such as argon, krypton, and xenon) to water lowers the freezing point, increases the boiling point, and changes the amount of heat absorbed and released when a liquid is cooled or heated.

The addition of an inert gas is used to eliminate the risk of oxygen poisoning of hot metal parts, it is used as an inert gas to control the reaction of chemicals, and it is used to create a blanket to decrease the temperature of the space. When inert gas is added to the atmosphere, it changes the properties of the air in two ways; firstly, it reduces the amount of oxygen and increases the number of other gases, which slows the rate at which fire spreads. Secondly, it increases the speed at which sound waves propagate. 

Effects of Addition of inert gas:

1. Inert gases such as CO2, N2O, and CH4 are added into the atmosphere during combustion, which leads to the greenhouse effect. This greenhouse effect is the main cause of global warming. This may result in a warmer climate at the surface and higher temperatures in the troposphere.
2. They decrease the rate of ozone depletion.
3. The inert gases are also known to cause adverse health effects when the gases are present in sufficient quantities near the skin. This may lead to headaches, fatigue, dizziness, and nausea.
4. They are non-reactive and have a low chemical reactivity towards other substances. They are used to prevent the oxidation of substances being used and also in gas absorption, where inert gas is used to absorb unwanted gases from gaseous streams.
5. Addition of inert gas in chemistry has different effects on the chemical system as it acts as a carrier of electrons. Its inert nature means that it will not react and thus acts as a carrier for electrons. Addition of inert gas in a chemical system can be a catalyst for chemical reactions.
6. The rate of a reaction increases or decreases when inert gas is added to the reaction mixture. The effect is not due to the amount of gas present but due to the presence of the gas.
7. The addition of inert gas to a chemical reaction can speed up the reaction. This is because the reaction of the gas is very low, thus minimising the amount of energy needed to react the substance. It can be used to make organic reactions run at higher speeds, allowing the reaction to occur more efficiently.
8. The presence of inert gases increases the freezing point of water considerably and the boiling point of alcohol considerably. These properties are due to the freezing point depression caused by the presence of inert gases and also because of the increased vapour pressure of the mixture. 

Examples of Addition of inert gas:

1. CO2 is added to keep the pH in the solution constant, and O2 is added to maintain a constant pressure.
2. Sodium bicarbonate is added to water to produce sodium carbonate and hydrogen gas.
3.  Adding carbon dioxide to water results in the formation of carbonic acid. 
4. Vinegar is added to water to produce a solution of acetic acid. 

Conclusion:

The addition of inert gas to a chemical reaction can affect the outcome of the reaction and how easily the reaction takes place. The addition of inert gas to a reaction will slow the reaction down or even make the reaction impossible. There are many effects of addition of inert gas; some negative and some positive. This addition may add to global warming and cause some health hazards but it is essential for laboratories and industries for them to function smoothly. The addition of inert gases prevent oxidation, act as catalysts, increase or decrease the rate of reaction and increase or decrease the melting or boiling point.