Problem 45 - Chemistry Matter and Change

Question

How many electrons are shared between two carbon at oms in each of the following carbon-carbon bonds? a. single bond b. double bond c. triple bond

Step-by-Step Solution

Answer

a. 1 pair (2 electrons) b. 2 pairs (4 electrons) c. 3 pairs (6 electrons)

Step 1: Understanding Single Bonds

A single covalent bond forms when two atoms share one pair of electrons. For carbon-carbon single bonds, this means that there is one pair of electrons shared between the two carbon atoms.

Step 2: Exploring Double Bonds

A double bond occurs when two pairs of electrons are shared between two atoms. In carbon-carbon double bonds, two pairs of electrons are shared.

Step 3: Analyzing Triple Bonds

A triple bond involves three pairs of electrons being shared between the two atoms. In a carbon-carbon triple bond, three pairs of electrons are shared.

Key Concepts

Single Bond

In covalent bonding, a single bond is the simplest type of bond formed between two atoms. When two atoms share a pair of electrons, they create a single covalent bond. This is indicated by a single line connecting the atoms, such as C-C in chemical structures.

In the case of carbon atoms, when they form a single bond, only one pair of electrons is shared. This sharing occurs because each carbon atom contributes one electron to the bond, allowing them to keep their outer electron shells more stable.

• A single bond consists of one shared pair of electrons.
• It is usually represented by a single line between two atoms in structural formulas.
• Single bonds are the longest and weakest compared to double and triple bonds.

In compounds where carbon atoms are linked by single bonds, like alkanes, these bonds allow for free rotation, providing flexibility to the molecular structure. This versatility makes single-bonded carbon chains a vital part of many organic molecules.

Double Bond

A double bond is a stronger form of covalent bonding involving the sharing of two pairs of electrons between two atoms. This is illustrated by a double line, like C=C, when drawing chemical structural formulas.

In the context of carbon-carbon interactions, a double bond means that two pairs of electrons are shared between the atoms. Each carbon atom effectively shares two of its electrons with the other, resulting in a stronger connection than that provided by a single bond.

• A double bond includes two shared pairs of electrons.
• It is depicted by double lines between two atoms in structural diagrams.
• Double bonds are shorter and stronger than single bonds, offering less flexibility due to restricted rotation.

Due to this stronger bond, molecules with double bonds, such as alkenes, often have different characteristics compared to their single-bonded counterparts. The rigidity imparted by double bonds can influence the shape and reactivity of molecules.

Triple Bond

In terms of covalent bonds, a triple bond is the most robust type typically found between carbon atoms. This type of bond involves the sharing of three pairs of electrons, and is drawn as a triple line like C≡C in molecular formulas.

During the formation of a carbon-carbon triple bond, each carbon atom shares three of its electrons with its partner, making for an extremely strong bond. This strength results from the closeness of the atoms and the number of paired electrons exchanged.

• A triple bond consists of three shared pairs of electrons.
• Triple lines in structural representations depict triple bonds.
• They are shorter and stronger than both single and double bonds, offering the least flexibility.

Molecules featuring triple bonds, such as alkynes, are characterized by their rigidity and often possess significant reactivity. The stiffness of triple-bonded structures limits their rotation, giving these molecules distinctive chemical properties.