Lithium Iodide Formula – Structure, Properties, Uses, Sample Questions

Lithium is a type of metal consumed in food, mainly grains, and vegetables. Various forms are used in small amounts of supplements. Lithium is present in trace amounts in almost all rocks, so it gets its name from the Greek word lithos, meaning stone. The iodide ion is the I^– ion. Compounds with iodine in the formal oxidation state -1 are called iodides. In everyday life, iodide is most commonly encountered as a component of salt iodide, which is mandated by many governments. Globally, iodine deficiency affects 2 billion people and is the leading cause of preventable mental retardation.

Lithium Iodide

It is an inorganic compound that combines lithium and iodine to form lithium iodide. It can also be easily identified because it changes color from white to yellow when iodine is formed by the oxidation of iodide in air. In addition, it may exist in the form of various hydrates, such as a monohydrate, dehydrate, and trihydrate. Lithium iodide also crystallizes from a sodium chloride motif (NaCl motif).

Lithium Iodide Formula

Lithium iodide is a compound composed of lithium and iodine that turns yellow when iodine is oxidized to iodine and exposed to air. The chemical formula is LiI. In this article, we will discuss the formula of lithium iodide, its chemical structure and formula, and its many uses of lithium iodide.

Structure of Lithium Iodide

Lithium iodide has a chemical formula  LiI and a molar mass or molecular weight of 133.85 g/mol. To form lithium iodide, lithium cations (Li⁺) react with iodine anions (I^–) to form lithium iodide. In the general expression of organic chemical formulas, the structure of Lithium iodide is :

Preparation of Lithium Iodide

In the laboratory, it can be synthesized by combining lithium sulfide and strontium iodide, which can be expressed as a bidirectional decomposition reaction as shown below.

Li₂S + SrI₂ → SrS + 2LiI

Physical Properties of Lithium Iodide

• The appearance of lithium iodide is a white crystalline powder.
• The molecular formula of lithium iodide is LiI.
• Melting Point is 469°C.
• Boiling Point is 1171°C.
• The density is 4.08 g/cm³.
• Molar Mass is 133.85 g/mol.
• The solubility of lithium iodide is Water Soluble.

Chemical Properties of Lithium Iodide 

• Liquid bromine and solid lithium iodide react to form solid lithium bromide and solid iodine.

Br₂(l) + LiI(s) → LiBr(s) + I₂(s)    

• LiI (lithium iodide) is also used in organic synthesis to cleave CO bonds. It converts methyl esters to carboxylic acids.

RCO₂CH₃ + LiI → RCO₂Li + CH₃I

• The pH of lithium iodide is a measure of the hydrogen ion concentration and is a measure of the acidity or alkalinity of a solution. The pH scale is usually between 0 and 14.
• To determine whether a substance is an acid or a base of lithium iodide, count the number of hydrogen atoms in each substance before and after the reaction.
• Atomic Properties of lithium iodide are crystal structure Face-centered cubic lattice.

Uses of Lithium Iodide

• It is used as an electrolyte in high-temperature batteries.
• Used in organic synthesis to break C–O bonds.
• Used as phosphor for neutron detection.

Sample Questions 

Question 1: Why does Lil covalently bond in nature?

Answer: 

Lithium Halide is a covalent bond due to the high polarization power of lithium ions. Li+ ions are very small in size and have a high tendency to distort the electron cloud around the halide ions of the negative ions.

Question 2: Is lithium iodide a salt?

Answer: 

One of the ways to obtain lithium iodide is the interaction of hydroxide with hydroiodic acid. The resulting salt can be purified by recrystallization. Lithium (I) iodide can also be prepared by neutralizing lithium (I) carbonate with hydroiodic acid. The resulting salt can be purified by recrystallization.

Question 3: Why is lithium iodide soluble in water?

Answer: 

LiF has very low hydration energy due to high lattice enthalpy and is therefore insoluble. However, in LiI, the lattice energy is small and the enthalpy of hydration is large because of the low lattice energy, so it is soluble in water.

Question 4: Why are lithium salts insoluble in water?

Answer: 

Lithium carbonate is less soluble because the electrostatic attraction between the very small lithium cations and carbonate anions is greater.

Question 5: Where is lithium chloride used?

Answer: 

Lithium chloride is primarily used to produce lithium metal by electrolysis of LiCl/KCl melts at 450°C (842°F). LiCl is also used as a flux for aluminum brazing of automotive parts. Used as a dehumidifier for airflow drying.

Question 6: Why does lithium have the most covalent properties? 

Answer: 

As the lithium compound is the smallest atom in group 1, it is covalent in nature because of the greater attraction between the outer electrons and the nucleus. Therefore, it is very difficult to donate electrons to other elements to form compounds using ionic bonds.

Question 7: Is lithium a hard drug?

Answer: 

“It’s the most mysterious drug in psychiatry,” says Demo Chuang, a biologist at the National Institute of Mental Health. “He is very small but very powerful.” Unlike other psychoactive chemicals such as large complex molecules like Prozac (fluoxetine) or Abilify (aripiprazole), lithium is very simple.