How many `sigma` bonds and `pi` bonds are present in `CH_(2)=C=CH_(2)` ?

Options

A. `6 sigma` and `1 pi`
B. `8 sigma` and `0 pi`
C. `4 sigma` and `4 pi`
D. `6 sigma` and `2 pi`

Answer

To determine the number of sigma (σ) and pi (π) bonds in the compound \( CH_2=C=CH_2 \), we can follow these steps:

### Step 1: Draw the Structure
First, we need to visualize the structure of the compound. The compound \( CH_2=C=CH_2 \) can be represented as follows:

```
H H
\ /
C
// \
C C
\ /
H H
```

### Step 2: Identify the Bonds
In the structure, we can identify the types of bonds present:
- The carbon atoms are connected by double bonds.
- Each carbon atom is also connected to hydrogen atoms.

### Step 3: Count the Sigma Bonds
- Each single bond is a sigma bond.
- Each double bond consists of one sigma bond and one pi bond.

Now, let's count the sigma bonds:
1. The first carbon (C) is bonded to two hydrogens (H), which gives us 2 sigma bonds.
2. The first carbon (C) is bonded to the second carbon (C) through a double bond, which contributes 1 sigma bond.
3. The second carbon (C) is bonded to the third carbon (C) through another double bond, contributing another sigma bond.
4. The third carbon (C) is bonded to two hydrogens (H), contributing 2 more sigma bonds.

So, the total number of sigma bonds is:
- From C-H bonds: 2 (from the first carbon) + 2 (from the third carbon) = 4
- From C-C bonds: 1 (from the first double bond) + 1 (from the second double bond) = 2

Total sigma bonds = 4 + 2 = 6

### Step 4: Count the Pi Bonds
Now, let's count the pi bonds:
- Each double bond has 1 pi bond.
- There are 2 double bonds in the structure.

Total pi bonds = 2 (1 from each double bond)

### Final Count
- Total Sigma Bonds = 6
- Total Pi Bonds = 2

Thus, in \( CH_2=C=CH_2 \), there are **6 sigma bonds** and **2 pi bonds**.

### Answer
- Sigma bonds: 6
- Pi bonds: 2

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