The high density of water compared to ice is due to
(a)hydrogen bonding interactions
(b)dipole -dipole interactions
(c)dipole - induced dipole interactions
(d)induced dipole -induced dipole interactions

Options

A. hydrogen bonding interactions
B. dipole -dipole interactions
C. dipole - induced dipole interactions
D. induced dipole -induced dipole interactions

Explanation

To solve the question regarding why the density of water is higher than that of ice, we can follow these steps:

### Step 1: Understand the Structure of Water
Water (H₂O) has a bent molecular structure due to the two hydrogen atoms bonded to a central oxygen atom. The oxygen atom is more electronegative than hydrogen, which leads to a partial negative charge on the oxygen and partial positive charges on the hydrogen atoms.

**Hint:** Recall the molecular geometry and polarity of water.

### Step 2: Identify the Type of Intermolecular Forces
In liquid water, the molecules are held together by intermolecular hydrogen bonds. Each water molecule can form hydrogen bonds with multiple neighboring water molecules (typically 3 to 4, but can be more).

**Hint:** Remember that hydrogen bonds are strong compared to other types of intermolecular forces.

### Step 3: Compare Liquid Water and Ice
In the solid state (ice), water molecules arrange themselves in a cage-like structure due to hydrogen bonding. This arrangement creates significant empty spaces or vacancies between the molecules, leading to a lower density.

**Hint:** Think about how the arrangement of molecules affects the overall volume and density.

### Step 4: Conclude the Reason for Density Differences
The cage-like structure in ice causes it to occupy more volume than the liquid form of water, resulting in a decrease in density. Therefore, the high density of water compared to ice is primarily due to hydrogen bonding interactions.

**Hint:** Consider how the arrangement of molecules in a solid versus a liquid affects their density.

### Final Answer
The correct answer is (a) hydrogen bonding interactions.