The pair of electrons in the given carbanion, `CH_(3)C-=C^(Theta)` is present in which of the following orbitals?

Options

A. `sp`
B. `2p`
C. `sp^(3)`
D. `sp^(2)`

Explanation

To determine the orbital in which the pair of electrons in the carbanion `CH3C≡C^-` is present, we can follow these steps:

### Step 1: Identify the Structure
The given carbanion is `CH3C≡C^-`. This indicates that we have a carbon atom bonded to three hydrogen atoms (CH3) and a carbon-carbon triple bond (C≡C) with a negative charge on one of the carbon atoms.

### Step 2: Determine Hybridization
To find the hybridization of the carbon atom with the negative charge, we need to analyze its bonding:
- The carbon with the negative charge is involved in a triple bond with another carbon atom.
- A triple bond consists of one sigma bond and two pi bonds.
- The carbon atom in a triple bond is typically sp-hybridized because it uses one s orbital and one p orbital to form the sigma bond, while the other two p orbitals are used to form the two pi bonds.

### Step 3: Count the Bonds
In the carbanion `CH3C≡C^-`, we have:
- One sigma bond from the C-H bond (from CH3).
- One sigma bond from the C-C bond (the triple bond).
- Two pi bonds from the C≡C triple bond.

### Step 4: Analyze the Negative Charge
The negative charge on the carbanion can be thought of as an additional electron. In the case of sp-hybridization:
- The sp hybridization involves one s orbital and one p orbital.
- The electrons in the carbanion will occupy the sp hybrid orbitals.

### Step 5: Conclusion
Thus, the pair of electrons in the given carbanion `CH3C≡C^-` is present in the sp orbital.

### Final Answer
The pair of electrons in the carbanion `CH3C≡C^-` is present in the **sp orbital**.

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