Question

Draw a compound that: (a) Has nine primary hydrogens (b) Has only primary hydrogens

Short answer

The compound is propane (\( CH_3-CH_2-CH_3 \)).

Step-by-step solution

Define Primary Hydrogen

Primary hydrogens are hydrogen atoms attached to a carbon atom that is only connected to one other carbon (a primary carbon).

Determine Structure Requirements

To have nine primary hydrogens, we need to have several primary carbon atoms. Each primary carbon can have up to three primary hydrogens only.

Construct the Carbon Backbone

We need three primary carbon atoms to have nine primary hydrogens (since each primary carbon has up to 3 hydrogens). These carbons can be arranged in a linear chain as: \[ \text{C-C-C} \]

Place Hydrogens Around Carbons

Connect each primary carbon with three hydrogens. The compound will look like this:\[CH_3-CH_2-CH_3 \]This is propane, where each of the nine hydrogens is primary.

Key concepts

Primary Hydrogen

In organic chemistry, understanding the role of primary hydrogen is key to deciphering larger molecular structures. Primary hydrogen refers to hydrogen atoms bound to a primary carbon. This means that the carbon atom holding the hydrogen is only connected to one other carbon atom. When considering how to identify or count primary hydrogens in a molecule, it's simple: just count the hydrogen atoms attached to primary carbons! In hydrocarbons like propane, it's easy to spot primary hydrogens in the structure, as they are directly tied to the final carbon atoms in the chain.

Primary Carbon

Primary carbon atoms play a critical role in defining the structure and characteristics of many organic compounds. A primary carbon is a carbon atom that is bonded to only one other carbon atom. This simple definition is crucial when analyzing hydrocarbon chains. These carbons are often found at the ends of the carbon chain, making them essential in understanding how primary hydrogens bond in molecules. Recognizing these carbons in structures like propane helps explain why specific hydrogens are labeled as primary.

Hydrocarbon Structure

Hydrocarbon structures form the backbone of many organic molecules in chemistry, providing a framework from which more complex molecules are built. Hydrocarbons are organic compounds composed exclusively of hydrogen and carbon atoms. They can be arranged in both linear or branched arrangements. For instance, a linear hydrocarbon might resemble something as straightforward as methane, while propane is a slightly more extended chain. To identify specific kinds of hydrogens, you must understand the arrangement of carbon chains, as this determines how many primary hydrocarbons are present.

Propane

Propane is a simple hydrocarbon that illustrates the principles of primary hydrogen and carbon bonds clearly. Its chemical formula is \(CH_3-CH_2-CH_3\), showing a chain of three carbon atoms. Each end carbon (primary carbon) holds three hydrogen atoms, resulting in primary hydrogens. In propane, these hydrogens are all primary, making it an excellent example to understand these concepts. Remember, in propane's molecule, there are always nine primary hydrogens available, aligning with owning two primary carbons.