What is I2? Important knowledge about I2

1. I₂ DEFINITION

I₂, also known as Iodine, is a chemical element with the symbol I and atomic number 53 in the periodic table. Iodine belongs to the Halogen group, occupying the 5th position in Group VIIA.

1.1. Common name: Iodine
1.2. English name: Iodine
1.3. Atomic number: 53
1.4. Atomic weight: 126.90447(3) u. An I₂ molecule is composed of two Iodine atoms bonded together by a single covalent bond.
1.5. Ion structure: Iodine typically forms the I− ion when participating in chemical reactions.

2. I₂ PROPERTIES

2.1. Physical properties of I₂: Iodine is a solid at room temperature, with a dark purple color. Iodine gas is purple. The smell of Iodine is very distinctive and unpleasant.
2.2. Chemical properties of I₂: Iodine has strong oxidizing ability, reacts with metals to form iodide salts, with alkali to form iodates…

3. COMMON CHEMICAL EQUATIONS WITH I₂

Reactions with metals, acids, non-metals, salts… For example:

• I₂ + 2Na -> 2NaI
• H₂SO₄ + I₂ -> H₂S + 2HI + O₂
• I₂ + H₂ -> 2HI
• I₂ + 2KCl + 2KCl + I₂ ->
• I₂ + 2KI + 2KI + I₂ ->

4. I₂ PREPARATION

4.1. Laboratory preparation of I₂: Iodine can be prepared from seawater by adding chlorine to oxidize the iodide in the seawater into iodine.

4.2. Industrial preparation of I₂: Iodine is prepared from iodide salts during starch extraction. The iodide salt is oxidized by chlorine gas to form iodine.