Question

question 42 of 49

match the molecular geometry (from the answer bank) to each labeled atom in the structure.

answer bank
bent trigonal pyramidal
trigonal planar linear
tetrahedral

structure:

• first ch₂ (double bond c)
• ch (single bond to ch₂, double bond to ch₂? wait, no, the structure is:

ch₂ (double bond to ch)
|
ch (single bond to ch₂)
|
ch₂ (single bond to ch₂)
|
ch₂ (single bond to c with triple bond)
|
c (triple bond to c)
|
c (single bond to h)

wait, the image shows:
top: ch₂ (double bond to ch)
then ch (single bond to ch₂)
then ch₂ (single bond to ch₂)
then ch₂ (single bond to c with triple bond)
then c (triple bond to c)
then c (single bond to h)

arrows point to each of these atoms: ch₂ (double bond), ch, ch₂, ch₂, c (triple bond c), c (single bond h).

answer bank options: bent, trigonal pyramidal, trigonal planar, linear, tetrahedral.

Explanation:

Step1: Analyze top $\text{CH}_2$

The top $\text{CH}_2$ has a carbon with 3 electron domains (1 double bond, 2 single bonds to H), no lone pairs. Electron domain geometry = molecular geometry: trigonal planar.

Step2: Analyze middle $\text{CH}$

The $\text{CH}$ has a carbon with 3 electron domains (1 double bond, 1 single bond to $\text{CH}_2$, 1 single bond to H), no lone pairs. Geometry: trigonal planar.

Step3: Analyze first $\text{CH}_2$ (below $\text{CH}$)

This $\text{CH}_2$ has a carbon with 4 electron domains (4 single bonds: 2 to H, 1 to $\text{CH}$, 1 to $\text{CH}_2$), no lone pairs. Geometry: tetrahedral.

Step4: Analyze second $\text{CH}_2$ (below first $\text{CH}_2$)

This $\text{CH}_2$ has a carbon with 4 electron domains (4 single bonds: 2 to H, 1 to upper $\text{CH}_2$, 1 to $\text{C}$), no lone pairs. Geometry: tetrahedral.

Step5: Analyze upper $\text{C}$ (in triple bond)

This carbon has 2 electron domains (1 triple bond, 1 single bond to $\text{CH}_2$), no lone pairs. Geometry: linear.

Step6: Analyze lower $\text{C}$ (in triple bond)

This carbon has 2 electron domains (1 triple bond, 1 single bond to H), no lone pairs. Geometry: linear.

Answer:

1. Top $\text{CH}_2$: trigonal planar
2. Middle $\text{CH}$: trigonal planar
3. First $\text{CH}_2$ (below $\text{CH}$): tetrahedral
4. Second $\text{CH}_2$ (below first $\text{CH}_2$): tetrahedral
5. Upper $\text{C}$ (triple bond): linear
6. Lower $\text{C}$ (triple bond): linear