What is Dioxygen?
Dioxygen, one of the common allotropes of elemental oxygen, and it is represented with the chemical formula O2. It is generally known as oxygen, but to avoid confusion with elemental oxygen, it is also called dioxygen, molecular oxygen, or oxygen gas. Oxygen gas reacts with almost all the elements with the exception of noble gases. The resulting compound is known as oxides. Oxygen gas is very important for combustion, though it is not flammable on its own. It is also a life-giving gas as mammals breathe in oxygen to live, as it helps to release energy.
Laboratory Preparation of Dioxygen
There are numerous ways of preparing dioxygen in the laboratory.
Catalytic decomposition of Sodium Potassium Chlorate with Magnesium dioxide as the catalytic produces dioxygen.
\[ 2KClO_{3} \rightarrow 2KCl + 3O_{2} \]
This reaction occurs on heating, in the presence of MnO2 at 420K.
Thermal decomposition of metal oxides with relatively low electrode potential in the electrochemical series like that of Mercury and Silver oxides etc. produces Dioxygen.
\[2HgO (s) \rightarrow 2Hg (l) + O_{2} (g)\]
\[ 2PbO_{2} (s) \rightarrow 2PbO (s) + O_{2} (g) \]
Salts rich in oxygen, like nitrates and permanganates, produce Dioxygen when decomposed thermally.
\[ 2KNO_{3} \rightarrow 2KNO_{2} + O_{2} \]
\[ 2KMnO_{4} \rightarrow K_{2}MnO_{4} + MnO_{2} + O_{2} \]
\[2NaNO_{3} \rightarrow 2NaNO_{2} + O_{2} \]
The decomposition of Hydrogen Peroxide also produces oxygen and to increase the rate of decomposition, manganese(IV) oxide is added as a catalyst.
\[2H_{2}O_{2}(aq) \rightarrow 2H_{2}O(l) + O_{2} (g)\]
Industrial Production of Oxygen
There are two primary methods used for the industrial production of O2 from the air.
Fractional distillation of liquified air with N2 distilling as a vapor while O2 is left as a liquid. Here liquid air is a mixture of liquid Nitrogen and liquid Oxygen. Nitrogen is more volatile because of the lower boiling point. It boils up first, leaving behind the pure oxygen.
Another method includes passing clean, dry air through one bed of a pair of zeolite molecular sieves, which absorbs the N2 gas, and delivers the gas which is 90%-93% oxygen.
Physical Properties of Dioxygen
It’s an odorless, colorless, and tasteless gas.
It is heavier than air with a density of 1.429 g/L.
It is slightly soluble in water, which is just sufficient to support aquatic life.
The melting point of oxygen is around 54.36 K and the Boiling point is around 90.188 K.
Oxygen exists in all three forms, i.e solid, liquid, and gas depending upon the temperature and pressure.
Chemical Properties
It reacts directly with almost all the metals and non-metals to give oxides of their respective elements.
\[4Na + O_{2} \rightarrow 2Na_{2}O \](With Metal)
\[C + O_{2} \rightarrow CO_{2} \](With Non-metal)
It is paramagnetic in nature.
Oxygen normally does not react with acids and bases.
Oxygen is a good oxidant and hence supports combustion.
\[Fuel + O_{2} \rightarrow CO_{2} + H_{2}O\]
Example, CH4 + O2 ⟶ CO2 + H2O
Oxygen, along with moisture, is responsible for the formation of rust on the iron.
\[Fe + O_{2}+ H_{2}O ⟶ Fe_{2}O_{3}n.H_{2}O \](Hydrated Iron Oxide)
Uses of Dioxygen
Dioxygen is vital for the respiration process.
It is used in oxygen cylinders which are used in hospitals and for mountaineering.
It is used for welding and cutting metals in the form of oxy-acetylene.
Oxygen gas combines with acetylene gas and produces an oxy-acetylene flame used for cutting and welding metals.
It is used in rocket fuel in liquid form.
It is used in the production of Nitric acid.
It is used for artificial respiration mixed with Carbon dioxide or methane.
Oxygen is used in laser cutting.
Oxygen is used in combustion processes. Materials that do not normally burn in air, burn easily in oxygen, so mixing oxygen with air enhances the combustion process.
Oxygen is used in water treatment processes, for purifying wastewater and treating sewage.
Fun Facts About Dioxygen
21 % of the earth’s atmosphere is made up of oxygen gas.
Warm water holds less dissolved oxygen than cold water because molecules are moving faster in warm water than cold water which allows oxygen to escape from the water.
The liver consumes the highest oxygen in the human body.
The health level of the water is measured by its oxygen gas content.
Pure oxygen is toxic. We can’t inhale 100 % Oxygen gas. In reality, we inhale air which is 21% oxygen.
The mass of the sun is made up of around 1% Oxygen.
Oxygen is essential for our respiratory system, whereas its allotrope ozone (O3) is highly toxic.
Conclusion
In the above-given information, Vedantu’s expert team has described Dioxygen - Preparation, Properties, and Uses which are to be studied by the students to provide and get the best result in the examination. Candidates appearing for chemistry examination should know that Dioxygen is an important chapter that has a good weightage and question based on this topic can be of any type multiple choice question, very short answer question, short answer question or long answers question, therefore students should prepare accordingly so that they are able to write answers properly and get prepared for the examination.
To study this chapter properly students should cover everything about these like dioxygen -preparation, properties and uses. Candidates can get involved in the studies with the help of Vedantu’s experts and get a better understanding of all the topics. Candidates should also study the important questions and the sample papers to get ready for the examination. Chemistry needs learning of the formulas so students can prepare revision notes for all the formulas and study thoroughly to get a command in the formulas of Chemistry.
FAQs on Dioxygen
1. Write down the reaction of oxygen with carbon, hydrogen, nitrogen, and ammonia?
1. Reaction with Nitrogen - Oxygen reacts with Nitrogen to form Nitrogen Dioxide at high temperatures. Firstly both react to form Nitric Oxide. Later on, nitric oxide further reacts with oxygen to form nitrogen dioxide.
N2 + O2 ⟶ NO
NO + O2 ⟶ NO2
2. Reaction with Hydrogen - Oxygen when heated with hydrogen forms water.
2H2 + O2 → 2H2O
3. Reaction with Ammonia - Oxygen reacts with ammonia to form nitric oxide and water. It is the reaction involved in Ostwald’s process for the manufacturing of Nitric acid.
NH4+O2→H2O+NO
4. Reaction with Carbon - Carbon when reacted with limited oxygen gives carbon monoxide, whereas with the excess supply of oxygen forms carbon dioxide
2C + O2 → 2CO
C + O2 → CO2
2. Does oxygen react with alkali metals?
Oxygen is highly reactive with the Alkali metals(Group I elements). Alkali metals
should be kept away from the oxygen in order to prevent getting oxidized. Metals
present in the bottom of the group are more reactive than the top.
With Lithium- Oxygen reacts with Lithium to form Lithium.
4Li + O2 → 2Li2O
With Sodium - Oxygen reacts with Sodium to form oxide and Peroxide.
4Na + O2 → 2Na2O
2Na + O2 → Na2O2
With Potassium - Oxygen reacts with Potassium to form peroxide and superoxide.
2K + O2 → 2K2O2
K + O2 → KO2
With Rubidium and Caesium - Both react to produce superoxides.
Rb + O2 → RbO2
3. How can I prepare for the chemistry chapter dioxygen?
Students can prepare for Chemistry chapter dioxygen with the help of the study material prepared by the most reliable platform Vedantu. Here the expert team has provided a detailed description of all the topics which students need to know in the chapter Dioxygen. After completing the study from the textbook students need to do some extra study which they can do with the notes and important questions prepared by experts of Vedantu students can download the free PDF file on Vedantu's site. They have provided quick links to help students in finding the links easily and download in just one click.
Preparing for your examinations needs a lot of hard work and study to score a good rank and pass with flying colors. Candidates can enroll themselves with Vedantu to get all the latest updates to prepare for your examination for chemistry. The tuition classes provided by Vedantu can be taken according to the time feasible for the student. They can make notes and clear all their doubts with expert teachers who are highly experienced and subject specialized to help students properly. Getting enrolled with Vedantu is very easy and it's free of cost you can get live trial classes and download free content to get an idea about this specialized platform.
4. What should be the pattern to write answers in chemistry chapter dioxygen?
If students want to score good marks then they should know the exact way to answer a question. If students follow the written pattern to answer questions they will surely score good marks. While preparing for your examination candidates should study the guidance issued by the board which will enable them to know the pattern which is to be followed to answer a question. Here are some tips you can follow to write an answer:
Use correct pen
Write chemistry formula clearly in a single line
Don't do overwriting
Answer in points
Don't exceed the word limit given to answer question
Give headings and subheadings to write answers
Use different pens to write headings
Students can log in to the Vedantu's portal which will help them to get all the latest updates regarding the upcoming examination and know the latest guidelines issued by the board regarding the pattern of question paper which will help them to practice beforehand and get prepared. Students should practice the sample question paper to manage their time duration and prepare to complete the question paper within the given time duration so that no question is left unanswered and candidates can score good marks in the final examination.
5. What are the key properties and uses of dioxygen?
Dioxygen has the following properties:
It is a colorless, odorless diatomic gas that is paramagnetic in nature
It is a highly reactive non-metal.
Easily dissolves in cold water
This diatomic gas is a powerful oxidizer.
2SO2+O2→2SO3
After fluorine, it is the second most electronegative element.
When dioxygen combines with metals or nonmetals, it forms oxides of the corresponding element.
2Ca+O2→2CaO
Uses of Dioxygen
Oxygen is used in a variety of ways. Oxygen is utilized in the following ways:
In medicine, as an oxygen supplement.
For the purpose of breathing.
In the smelting of iron ore to make steel industries.
Metal cutting and welding are two of the most common applications.
In water treatment and rocket fuel as an oxidizer.