Question

Тема: Химическая связь Какая ковалентная связь называется σ- связью и какая π-связью? Рассмотрите на примере молекул азота и этилена.

Answer 1

Сигма связи - это грубо говоря одинарные связи, а пи связи - это те связи, которые образуют двойные, тройные.
В молекуле азота(N≡N) 1 σ-связь и 2 π-связи. В молекуле этилена(СH₂=CH₂) 5 σ-cвязей и 1 π-связь.

Answer 2

Kovalentnaya Svaz and Its Types

Kovalentnaya svyaz (covalent bond) is a type of chemical bond that involves the sharing of electron pairs between atoms. There are two main types of covalent bonds: σ (sigma) bond and π (pi) bond.

Sigma (σ) Bond

A σ bond is formed by the head-on overlap of atomic orbitals along the bond axis. It allows for free rotation around the bond axis. In the case of nitrogen (N2) molecule, the formation of σ bonds can be illustrated as follows: - In the nitrogen molecule (N2), each nitrogen atom contributes three of its electrons to form three σ bonds with the other nitrogen atom.

Pi (π) Bond

A π bond is formed by the side-to-side overlap of atomic orbitals above and below the bond axis. It does not allow for free rotation around the bond axis. In the case of ethylene (C2H4) molecule, the formation of π bonds can be illustrated as follows: - In the ethylene molecule (C2H4), the carbon-carbon double bond consists of one σ bond and one π bond. The π bond is formed by the overlap of the p orbitals of the carbon atoms.

In summary, σ bonds are formed by the head-on overlap of atomic orbitals, allowing free rotation, while π bonds are formed by the side-to-side overlap of atomic orbitals, restricting rotation.

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