Answer :
Building and analyzing molecular structures allows us to understand the spatial arrangement and bond angles of atoms in molecules.
For this task, we choose two molecules: D-glucose and acetylsalicylic acid (aspirin). Let’s analyze them:
### D-Glucose ([tex]$C_6H_{12}O_6$[/tex])
D-glucose is a common sugar with the molecular formula [tex]$C_6H_{12}O_6$[/tex]. To determine the structure and geometry, follow these steps:
1. Draw the Structure:
D-Glucose is typically found in its cyclic form, resembling a six-membered ring (pyranose form). It has a single oxygen atom in the ring and five carbon atoms forming the ring, with additional hydroxyl and hydrogen groups attached.
2. Identify Central Atoms:
Circle three different central atoms:
- Carbon atom 1 (C1)
- Carbon atom 2 (C2)
- Oxygen atom in the ring (O)
3. Determine Molecular Geometry:
- C1 and C2: Both these are carbon atoms bonded to four different atoms/groups. The geometry around each carbon is tetrahedral, with bond angles close to [tex]$109.5^\circ$[/tex].
- Ring Oxygen (O): This oxygen is bonded to two carbons. In the context of tetrahedral geometry around carbon atoms, the bond angles involving oxygen are slightly adjusted but close to [tex]$109.5^\circ$[/tex].
### Acetylsalicylic Acid (Aspirin) ([tex]$C_9H_8O_4$[/tex])
Acetylsalicylic acid is commonly known as aspirin, with the molecular formula [tex]$C_9H_8O_4$[/tex]. The molecule has a benzene ring attached to a carboxyl group and an ester group.
1. Draw the Structure:
This molecule has a benzene ring of six carbon atoms, with a carboxyl group ([tex]$-COOH$[/tex]) and an ester group ([tex]$-COOCH_3$[/tex]) attached.
2. Identify Central Atoms:
Circle three different central atoms:
- One Carbon atom in the benzene ring (C1)
- Carbon atom in the carboxyl group (C2)
- Oxygen atom in the ester group (O)
3. Determine Molecular Geometry:
- C1 (in benzene ring): Each carbon in the benzene ring forms three sigma bonds (two with adjacent carbons and one with hydrogen or a substituent) and one delocalized pi bond. The geometry is planar trigonal with bond angles of [tex]$120^\circ$[/tex].
- C2 (carboxyl group): This carbon atom forms three sigma bonds (one with a carbon, one with an oxygen, and one with another oxygen - double bond). The geometry around this carbon is planar trigonal, with bond angles of [tex]$120^\circ$[/tex].
- Oxygen in ester group (O): In the ester group, oxygen is bonded to two carbons. If you consider the lone pairs, the geometry around this oxygen is bent/angular with bond angles roughly around [tex]$104.5^\circ$[/tex].
By analyzing these molecules, you gain insight into their spatial configuration and how different atoms and groups are arranged in three dimensions. This exercise is essential for understanding chemical reactivity, physical properties, and biological interactions.
For this task, we choose two molecules: D-glucose and acetylsalicylic acid (aspirin). Let’s analyze them:
### D-Glucose ([tex]$C_6H_{12}O_6$[/tex])
D-glucose is a common sugar with the molecular formula [tex]$C_6H_{12}O_6$[/tex]. To determine the structure and geometry, follow these steps:
1. Draw the Structure:
D-Glucose is typically found in its cyclic form, resembling a six-membered ring (pyranose form). It has a single oxygen atom in the ring and five carbon atoms forming the ring, with additional hydroxyl and hydrogen groups attached.
2. Identify Central Atoms:
Circle three different central atoms:
- Carbon atom 1 (C1)
- Carbon atom 2 (C2)
- Oxygen atom in the ring (O)
3. Determine Molecular Geometry:
- C1 and C2: Both these are carbon atoms bonded to four different atoms/groups. The geometry around each carbon is tetrahedral, with bond angles close to [tex]$109.5^\circ$[/tex].
- Ring Oxygen (O): This oxygen is bonded to two carbons. In the context of tetrahedral geometry around carbon atoms, the bond angles involving oxygen are slightly adjusted but close to [tex]$109.5^\circ$[/tex].
### Acetylsalicylic Acid (Aspirin) ([tex]$C_9H_8O_4$[/tex])
Acetylsalicylic acid is commonly known as aspirin, with the molecular formula [tex]$C_9H_8O_4$[/tex]. The molecule has a benzene ring attached to a carboxyl group and an ester group.
1. Draw the Structure:
This molecule has a benzene ring of six carbon atoms, with a carboxyl group ([tex]$-COOH$[/tex]) and an ester group ([tex]$-COOCH_3$[/tex]) attached.
2. Identify Central Atoms:
Circle three different central atoms:
- One Carbon atom in the benzene ring (C1)
- Carbon atom in the carboxyl group (C2)
- Oxygen atom in the ester group (O)
3. Determine Molecular Geometry:
- C1 (in benzene ring): Each carbon in the benzene ring forms three sigma bonds (two with adjacent carbons and one with hydrogen or a substituent) and one delocalized pi bond. The geometry is planar trigonal with bond angles of [tex]$120^\circ$[/tex].
- C2 (carboxyl group): This carbon atom forms three sigma bonds (one with a carbon, one with an oxygen, and one with another oxygen - double bond). The geometry around this carbon is planar trigonal, with bond angles of [tex]$120^\circ$[/tex].
- Oxygen in ester group (O): In the ester group, oxygen is bonded to two carbons. If you consider the lone pairs, the geometry around this oxygen is bent/angular with bond angles roughly around [tex]$104.5^\circ$[/tex].
By analyzing these molecules, you gain insight into their spatial configuration and how different atoms and groups are arranged in three dimensions. This exercise is essential for understanding chemical reactivity, physical properties, and biological interactions.
