Water has abnormally high boiling point because

Options

A. its molecule is bent
B. its molecule is linear
C. it is associated by hydrogen bonding
D. none of the above

Explanation

**Step-by-Step Solution:**

1. **Understanding Boiling Point**: The boiling point of a substance is the temperature at which its vapor pressure equals the atmospheric pressure. For water, this occurs at 100 degrees Celsius under standard atmospheric conditions.

2. **Comparing with Other Substances**: To understand why water has an abnormally high boiling point, we can compare it with other similar molecular compounds, such as methane (CH4), which has a boiling point of -161.5 degrees Celsius. Despite having similar molecular weights, water's boiling point is significantly higher.

3. **Role of Hydrogen Bonding**: The primary reason for the high boiling point of water is the presence of hydrogen bonds. Hydrogen bonds occur when hydrogen is covalently bonded to a highly electronegative atom, such as oxygen. In water (H2O), each oxygen atom can form hydrogen bonds with neighboring water molecules due to its high electronegativity.

4. **Molecular Structure of Water**: The molecular structure of water (H2O) includes two hydrogen atoms bonded to one oxygen atom. The oxygen atom has two lone pairs of electrons, which also contribute to the molecule's polarity and ability to form hydrogen bonds.

5. **Effect of Hydrogen Bonds on Boiling Point**: The hydrogen bonds between water molecules create a strong intermolecular attraction. This means that more energy (in the form of heat) is required to break these bonds for the water to transition from a liquid to a gaseous state, resulting in a higher boiling point.

6. **Conclusion**: Therefore, the abnormally high boiling point of water can be attributed to the presence of hydrogen bonding and the molecular structure of water, which allows for strong intermolecular attractions.

**Final Answer**: Water has an abnormally high boiling point because it is associated with hydrogen bonding.

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