Which of the following is not true regarding the structure of benzene? a) the carbon-carbon bonds rapidly alternate between single and double bonds. b) the c-c-c bond angles are 120°. c) the hydrogen atoms are equivalent. d) the π bonds are completely conjugated.

a) The carbon-carbon bonds rapidly alternate between single and double bonds.

Explanation:

In benzene we have that the molecule is planar with an sp² hybridization that allow for three π bonds and the carbons atoms are also bonded together via sigma  a sp² hibridization as well as one hydrogen atom. The alternation of or conjugation of the π bond allow the delocalization of these electron along the whole ring.

Therefore, a) is false the carbon-carbon bonds rapidly alternate between single and double bond. The electrons in the π bonds are completely delocalized through the six atoms in the ring.

b) is true since we have a sp² hybridization.

c) and d) are true for the reasons given previously.

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.

2b2t

explanation:

2b2t