For each pair, give the relationship between the two compounds. Making models will be helpful.
(g)

Verified step by step guidance

1. Step 1: Analyze the structures of the two compounds provided in the image. Both compounds are aldoses, as they contain an aldehyde group (-CHO) at the top of the structure. Additionally, they have hydroxyl (-OH) groups attached to the carbon chain.
2. Step 2: Compare the stereochemistry of the hydroxyl (-OH) groups at each chiral center. A chiral center is a carbon atom bonded to four different groups. In the first compound, the configuration of the hydroxyl groups alternates as HO-H, H-OH, H-OH, and CH2OH. In the second compound, the configuration alternates as H-OH, HO-H, HO-H, and CH2OH.
3. Step 3: Determine the relationship between the two compounds based on the stereochemistry. If the compounds differ in the configuration of all chiral centers, they are enantiomers (non-superimposable mirror images). If they differ in the configuration of some but not all chiral centers, they are diastereomers.
4. Step 4: Verify the configurations at each chiral center. In this case, the compounds differ in the configuration at every chiral center. For example, the first chiral center in the first compound has the hydroxyl group on the left (HO-H), while in the second compound, it is on the right (H-OH). This pattern is consistent for all chiral centers.
5. Step 5: Conclude that the two compounds are enantiomers because they differ in the configuration of all chiral centers and are non-superimposable mirror images of each other.

Key Concepts

Fischer Projections

Fischer projections are a two-dimensional representation of three-dimensional organic molecules, particularly useful for depicting stereochemistry. In these projections, vertical lines represent bonds that extend behind the plane of the page, while horizontal lines represent bonds that come out towards the viewer. This format is especially helpful for visualizing the spatial arrangement of functional groups in carbohydrates and amino acids.

Stereoisomerism

Stereoisomerism occurs when compounds have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of their atoms. This can lead to different physical and chemical properties. In the context of the provided Fischer projections, the two compounds may represent different stereoisomers, which can be classified as enantiomers or diastereomers based on their specific configurations.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In the Fischer projections shown, the presence of hydroxyl (-OH) groups and an aldehyde (-CHO) group indicates that these compounds are likely sugars or sugar derivatives. Understanding functional groups is crucial for predicting the reactivity and properties of organic compounds.