The critical temperature of water is higher than that of `CO_2` because the `H_2O` molecule has

Options

A. fewer electrons than `O_2`
B. two covalent bonds
C. V-shape
D. dipole moment

Answer

To solve the question regarding why the critical temperature of water is higher than that of carbon dioxide, we can break down the reasoning into a series of logical steps:

### Step-by-Step Solution:

1. **Understanding Critical Temperature**:
- The critical temperature (Tc) is defined as the highest temperature at which a substance can exist in the liquid state. Above this temperature, the substance cannot be liquefied, regardless of the pressure applied.

2. **Factors Influencing Critical Temperature**:
- The critical temperature is influenced by the strength of intermolecular forces present in the substance. Stronger intermolecular forces lead to a higher critical temperature.

3. **Comparison of Water and Carbon Dioxide**:
- Water (H2O) and carbon dioxide (CO2) have different molecular structures and properties.
- Water has a bent (V-shaped) molecular structure, while carbon dioxide has a linear structure.

4. **Dipole Moment**:
- Water has a significant dipole moment due to its bent shape and the difference in electronegativity between hydrogen and oxygen. This means that water molecules have a positive and a negative end, leading to polar interactions.
- In contrast, carbon dioxide is a nonpolar molecule because the dipoles from the two C=O bonds cancel each other out due to its linear shape.

5. **Intermolecular Forces**:
- The presence of a dipole moment in water allows for stronger intermolecular forces, such as hydrogen bonding, which are not present in CO2.
- The stronger the intermolecular forces, the higher the value of the Van der Waals constant (A) in the critical temperature formula (Tc = 8A / 27Rb).

6. **Conclusion**:
- Since water has stronger intermolecular forces due to its dipole moment and hydrogen bonding, its critical temperature is higher than that of carbon dioxide.

### Final Answer:
The critical temperature of water is higher than that of CO2 because the H2O molecule has a significant dipole moment and exhibits hydrogen bonding.