Which one of the following compounds has sp-hybridisation?

Options

A. `CO_2`
B. `SO_2`
C. `N_2 O`
D. `CO`

Explanation

To determine which of the given compounds has sp-hybridization, we will analyze the hybridization of each compound: CO2, SO2, N2O, and carbon monoxide (CO).

### Step 1: Analyze CO2 (Carbon Dioxide)
1. **Lewis Structure**: The Lewis structure of CO2 shows that carbon is bonded to two oxygen atoms with double bonds.
2. **Bonding**: There are 2 sigma bonds and 2 pi bonds around the carbon atom.
3. **Hybridization**: Since there are 2 regions of electron density (2 sigma bonds), the hybridization of carbon in CO2 is **sp**.

### Step 2: Analyze SO2 (Sulfur Dioxide)
1. **Lewis Structure**: The Lewis structure of SO2 shows that sulfur is bonded to two oxygen atoms with one double bond and has one lone pair.
2. **Bonding**: There are 2 sigma bonds and 1 lone pair around the sulfur atom.
3. **Hybridization**: The total number of regions of electron density is 3 (2 sigma bonds + 1 lone pair), leading to **sp2** hybridization.

### Step 3: Analyze N2O (Nitrous Oxide)
1. **Lewis Structure**: The Lewis structure of N2O shows a nitrogen-nitrogen triple bond and a nitrogen-oxygen single bond.
2. **Bonding**: The central nitrogen has no lone pairs and is bonded to two nitrogen atoms (one with a triple bond and one with a single bond).
3. **Hybridization**: The central nitrogen has 2 regions of electron density (triple bond counts as one region), which leads to **sp** hybridization.

### Step 4: Analyze CO (Carbon Monoxide)
1. **Lewis Structure**: The Lewis structure of CO shows a carbon atom bonded to an oxygen atom with a triple bond.
2. **Bonding**: Carbon has one lone pair and one sigma bond.
3. **Hybridization**: The total number of regions of electron density is 2 (1 sigma bond + 1 lone pair), which indicates **sp** hybridization.

### Conclusion
The compounds with sp-hybridization are:
- CO2 (Carbon Dioxide)
- N2O (Nitrous Oxide)
- CO (Carbon Monoxide)

**Final Answer**: CO2, N2O, and CO all have sp-hybridization.