KNO2 Structure & Characteristics (13 Helpful Facts)

KNO₂ or Potassium nitrite is an inorganic compound of K⁺ and NO₂^–. Let us discuss some facts related to KNO₂ in detail.

KNO₂ or Potassium nitrite is hygroscopic substance with molar mass 85.10379 g/mol. It is deliquescent and its density is 1.914 g/cm³. Its melting point and boiling point is 440.02⁰ C and 537⁰ C respectively. It is found to be a good oxidising agent and is very toxic too.

Sometimes potassium nitrite can be mutagenic in nature. Let us discuss the structure, formal charge, angle, hybridisation and many other facts related to KNO₂ in this article.

How to draw KNO₂ Structure?

Crystal structure of a compound is obtained when atoms or group of atoms joined together. Let us look into the structure of KNO₂.

• The crystal structure of KNO2 is found through oscillating single crystal photographs.
• The results were spherical shaped granule crystals without face and was anhydrous.
• Its basic crystal structure is monoclinic with a,b,c values are 4.45 A⁰, 4.99 A⁰, 7.31 A⁰.
• The observed density is 1.915 g per cc and the number of molecules in the unit cell is 2.01.
• The rotation and laue photographs leads to the following monoclinic crystal structure of KNO_2.

KNO₂ Structure Shape

The shape of a molecule can be predicted by knowing its hybridization. Let us look into the shape of KNO₂.

The shape of KNO₂ structure is bent. KNO₂ is an ionic compound and its shape is determined by the shape of nitrite. Nitrite is bent molecule or v shaped molecule because nitrogen and oxygen both contain lone pairs.

KNO₂ Structure Formal Charge

Formal charge is a hypothetical charge given to an atom and it can be any integers. Let us calculate the formal charge of KNO₂.

The formal charge of KNO₂ is 0 for potassium and oxygen. Formal charge is 1 for nitrogen. The formal charge finding equation is

Formal charge= valence electrons — non bonding electrons — no. of bonds

• Formal charge of oxygen = 0
• Formal charge of potassium=0
• Formal charge of nitrogen = 1

KNO₂ Structure Angle

Angle can be distorted for certain molecules having lone pairs in the central atom. Let us look into the bond angle of KNO₂.

The bond angle of KNO₂ structure is 120⁰ due to the presence of lone pairs in nitrogen.

KNO₂ Structure Lone Pairs

Lone pairs or non bonding electrons are actually one thing. Let us know about the lone pairs in KNO₂.

The lone pairs in KNO₂ is 6. One oxygen has two, one has three, and nitrogen has one pair. On combining there are 6 lone pairs or 12 non bonding electrons found in potassium nitrite.

KNO₂ Valence Electrons

Valence Electrons are usually transferred between the atoms during chemical reactions. Let us research KNO₂ valence electrons.

There are 18 valence electrons in KNO₂ with one, nitrogen with 5 and oxygen with 6 .

KNO₂ Hybridization

Hybridisation is the formation of new orbitals as a result overlapping of atomic orbitals. Let us see the hybridisation in KNO₂.

The hybridisation of nitrite in KNO₂ is sp^{2 .} One 2s and two 2p orbitals of nitrogen overlaps to for sp² hybrid orbitals. The oxygen’s partially filled 2p orbitals share electrons with the sp² orbitals.

The unhybridised p orbital of oxygen overlaps with 2p orbital of nitrogen to make pi bond.

KNO₂ Solubility

Ionic compounds tend not to dissolve in non polar solvents. Let us examine KNO₂ solubility.

KNO₂ has been proven to be water soluble. It gets highly get dissolved in water and can’t even separate easily.KNO₂ is soluble in water because it is polar in nature.

KNO2 is soluble in the following solvents

• Ethanol
• Ammonia

Is KNO₂ Solid or Liquid?

Solids and liquids have definite volume and density but gas doesn’t have any volume. Let us see KNO₂ is solid or liquid.

KNO₂ is a solid substance. It is a crystalline substance which either white or yellow in color. It is powdered in nature.

Is KNO₂ Polar or Non Polar?

Polar substance has charged ions in it and has a definite value of dipole moment. Let us see whether KNO₂ is polar or not.

KNO₂ is a polar substance. K⁺ and NO₂^– ions comprises together to form KNO₂ which is polar. The electronegativity of potassium, nitrogen and oxygen is 0.82,3.04 and 3.44 .

Since there is huge difference in their electronegativity values and they are charged molecules they are polar compounds.

Is KNO₂ Acidic, Basic or Salt?

Acids and bases combines together to give the neutral substance called salt as a result of neutralisation reaction. Let us check about the acidity, basicity and salt like nature of KNO₂.

Strong bases and weak acids combine to generate the salt known as KNO₂.KNO₂ is formed when KOH a strong base reacts with HNO₂ a weak acid.

Here a strong base and weak acid is combined so the salt formed called KNO₂ is a basic salt with pH value is 8.40.

Is KNO₂ Electrolyte?

An electrolyte can conduct electricity easily in solution. Let us know do KNO₂ acts as an electrolyte or not.

KNO₂ is an electrolyte because its an ionic compound. It can dissociate well in water to give its corresponding ions from its lattice site. These ions can easily conduct electricity.

Is KNO₂ Ionic or Covalent?

Ionic and covalent compounds are two classes of compounds . Let us see KNO₂ is ionic or covalent.

KNO₂ is an ionic compound. Potassium donates one electron to NO₂ to form the cation K⁺and anion NO₂^– respectively. These ions are joined by the simple electrostatic force of attraction to form the compound.

Conclusion

KNO₂ or potassium nitrite is a inorganic salt used for manufacturing of heat transfer cells, as a food additive and preservative. It is stored away from combustible materials, acids and reducing agents in cool, dry ventilated locations.