Question

State the physical and chemical properties of $\mathrm{Oxygen}$

Answer 1

$\mathrm{Oxygen}$

• $\mathrm{Oxygen}$ is the second most abundant gas in the atmosphere. Air contains 21% of $\mathrm{Oxygen}\mathrm{gas}$.
• For the survival of the living organism, $\mathrm{Oxygen}$ is essential.
• Elemental representation of $\mathrm{Oxygen}$ is ${}_8{}^{16}\mathrm{O}$, where $8$ is the atomic number and $16$ is the mass number.
• The molecular formulae of $\mathrm{Oxygen}$ is ${\mathrm{O}}_2$.

Physical properties

• $\mathrm{Oxygen}$ is a colourless, odourless, and tasteless gas.
• It is slightly heavier than air.
• It is slightly soluble in water, therefore aquatic plants and animals use this dissolved $\mathrm{Oxygen}$ for respiration.
• $\mathrm{Oxygen}$ can be liquefied into bluish liquid on strong cooling (boiling point $-183°\mathrm{C}$).

Chemical properties.

• Combustibility: It is a good supporter of combustibility. Many elements except noble gases burn in $\mathrm{Oxygen}$.
• Action with litmus: Litmus does not show any colour change with $\mathrm{Oxygen}$. Hence it is neutral in nature.
• Burning of elements in Oxygen: Metals and non-metals burns in $\mathrm{Oxygen}$ to produce their respective oxides. The process involves the formation of oxide is known as an oxidation reaction.

$\mathrm{Metal}+\mathrm{Oxygen}\to \mathrm{Metallic}\mathrm{oxide}$

$\mathrm{Nonmetal}+\mathrm{Oxygen}\to \mathrm{Nonmetallic}\mathrm{oxide}$

(A) Reaction with metal: Metals burn-in $\mathrm{Oxygen}$ to produce metallic oxides.They are basic in nature.

Example : $\underset{\mathrm{Magnesium}}{2\mathrm{Mg}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Magnesium}\mathrm{oxide}}{2\mathrm{MgO}\left(\mathrm{s}\right)}$

(B) Reaction with non metal: Non-metal burns in $\mathrm{Oxygen}$ to produce non-metallic oxide.

Example : $\underset{\mathrm{Carbon}}{\mathrm{C}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$