At room temperature, water is a liquid with a molar volume of 18 ml. at 105°c and 1 atm pressure, water is a gas and has a molar volume of over 30 l. explain the large difference in molar volumes.

The molar volume of water depends on the degree of intermolecular interaction.

Water molecules are held together by intermolecular hydrogen bonds. The magnitude intermolecular hydrogen bonding is greatest in the solid and least in the gas phase.

Hence, in the liquid state, the molecules of water are closer together due to strong hydrogen bonding. At room temperature, water is liquid hence it has a lower molar volume of 18 mL.

At higher temperature such as  105°C , beyond the liquid range of water, the magnitude of intermolecular interaction in water is minimal hence water has a higher molar volume of 30 L because water molecules spread out; apart from each other.

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Here's what I get  

Explanation:

In the liquid phase, the molecules are touching each other.

In the gas phase, the molecules are far apart from each other (about 500 times their diameters), so they occupy more space.

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explanation:

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