Question

A new compound is made that has a \(\mathrm{C}-\mathrm{C}\) bond length of 1.15 \(\mathrm{A} .\) Is this bond likely to be a single, double, or triple \(\mathrm{C}-\mathrm{Cbond} ?\)

Short answer

The bond length of the new compound is 1.15 Å, which is shorter than the standard lengths of single, double, and triple carbon-carbon bonds. The most probable type of bond in the new compound is a triple \(\mathrm{C}-\mathrm{C}\) bond, but with some extra factors causing it to be even shorter.

Step-by-step solution

Identify the standard bond lengths of C-C single, double, and triple bonds

The standard bond lengths for carbon-carbon bonds are as follows: - \(\mathrm{C}-\mathrm{C}\) single bond: around 1.54 Å - \(\mathrm{C}=\mathrm{C}\) double bond: around 1.34 Å - \(\mathrm{C}\equiv\mathrm{C}\) triple bond: around 1.20 Å These comparisons will help us determine the bond type in the new compound.

Compare the given bond length to the standard bond lengths

The question provides the bond length of the new compound as 1.15 Å. Comparing this to the standard bond lengths, it seems that the given bond length is shorter than the standard triple bond length (1.20 Å) and much shorter than the double and single bond lengths.

Infer the type of bond in the new compound

Due to the bond length being shorter than all standard bond lengths (1.15 Å), we can infer that the bond in the new compound is likely to be a triple \(\mathrm{C}-\mathrm{C}\) bond, but with some extra factors causing it to be even shorter. It could be due to the presence of other elements, steric factors, or electronic effects. However, based on the data given, a triple bond is most likely for the new compound.

Key concepts

Chemical Bonding

Chemical bonding is the force that holds atoms together within molecules. It's crucial for creating the diverse array of substances found in the world, from the air we breathe to the materials that make up technology and living organisms. There are several types of chemical bonds, with covalent, ionic, and metallic bonds being the most common.

Covalent bonding occurs when atoms share electrons, ionic bonding results from the electrostatic attraction between oppositely charged ions, and metallic bonding is due to the attraction between metal ions and free-floating electrons. Understanding the nature of these bonds provides insights into a molecule's properties, such as stability, reactivity, and physical characteristics like melting and boiling points.

Covalent Bonds

Covalent bonds form when two atoms share one or more pairs of electrons, allowing each atom to achieve a full outer shell, mimicking the electron configuration of noble gases. These bonds can be single, double, or triple, depending on the number of shared electron pairs.

A single covalent bond involves one electron pair, a double bond involves two, and a triple bond involves three. These different bonds don't just imply the number of shared electrons but also significantly affect the strength and length of the bond between atoms. Typically, triple bonds are the strongest and shortest due to the greater number of shared electrons pulling the atoms closer together, whereas single bonds are the weakest and longest.

Bond Length Comparison

The bond length is the average distance between the nuclei of two bonded atoms. It is determined experimentally and can be affected by several factors, such as the nature of the bond and the presence of electron-withdrawing or electron-donating groups.

For carbon-carbon bonds, the average bond lengths tend to decrease as the number of shared electron pairs increases: single bonds are the longest, double bonds are shorter, and triple bonds are the shortest. However, variations can occur due to molecular strain or electronic effects. For instance, bond lengths might differ in cycles or when there are resonance structures. Knowing this, we can often predict the type of bond from its length, but extraordinary circumstances might lead to deviations from the norm. It's why, in complex cases, additional context and data are needed to accurately determine the bond type.