Which of the following statements is / are correct ?

Options

A. All carbon to carbon bonds contain a sigma bond and one or more `pi`- bonds
B. All carbon to carbon bonds are sigma bonds
C. All oxygen to hydrogen bonds are hydrogen bonds
D. All carbon to hydrogen bonds are sigma bonds

Answer

To determine which statements are correct regarding chemical bonding, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: All carbon to carbon bonds contain a sigma bond and one or more pi bonds.**
- This statement is **incorrect**. While carbon-carbon double and triple bonds do contain both sigma and pi bonds, single carbon-carbon bonds (like in ethane, CH3-CH3) consist only of a sigma bond and no pi bonds. Therefore, not all carbon-carbon bonds contain pi bonds.

2. **Statement 2: All carbon to carbon bonds are sigma bonds.**
- This statement is also **incorrect**. Although single carbon-carbon bonds are indeed sigma bonds, double bonds (like in ethene, CH2=CH2) consist of one sigma bond and one pi bond. Hence, not all carbon-carbon bonds are purely sigma bonds.

3. **Statement 3: All oxygen to hydrogen bonds are hydrogen bonds.**
- This statement is **incorrect**. While hydrogen bonds can form between water molecules (where an oxygen atom of one water molecule interacts with a hydrogen atom of another), the bond between oxygen and hydrogen in water (H2O) is a covalent bond. Therefore, not all oxygen-hydrogen bonds are hydrogen bonds.

4. **Statement 4: All carbon to hydrogen bonds are sigma bonds.**
- This statement is **correct**. In all carbon-hydrogen bonds, the bond formed is a sigma bond. Carbon can only form a sigma bond with hydrogen because hydrogen has only one electron to share, and thus cannot form pi bonds with carbon.

### Conclusion:
The only correct statement is **Statement 4**: All carbon to hydrogen bonds are sigma bonds.

### Final Answer:
**Only Statement 4 is correct.**

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