When water is heated from `0^@C`, its volume

Options

A. increases
B. decreases till `4^@C`
C. remains the same
D. first increases then decreases

Answer

To solve the question regarding the behavior of water's volume when heated from 0°C, we can follow these steps:

### Step 1: Understand the Concept of Density and Volume
Density is defined as mass per unit volume (Density = Mass/Volume). When the temperature of water changes, its density also changes, which in turn affects its volume.

**Hint:** Remember that density and volume are inversely related when mass is constant.

### Step 2: Analyze the Behavior of Water from 0°C to 4°C
When water is heated from 0°C to 4°C, it behaves unusually compared to most substances. As the temperature increases, the density of water actually increases until it reaches 4°C.

**Hint:** Consider how temperature affects the arrangement of water molecules and their density.

### Step 3: Determine the Volume Change from 0°C to 4°C
Since the density of water increases as it is heated from 0°C to 4°C, the volume of water must decrease during this temperature range. This is because an increase in density (with constant mass) leads to a decrease in volume.

**Hint:** Think about how the molecules are packed more closely together as the temperature approaches 4°C.

### Step 4: Identify the Behavior at 4°C
At 4°C, water reaches its maximum density, meaning that the volume of water is at its minimum for this temperature range.

**Hint:** This is a unique property of water; most substances expand when heated.

### Step 5: Analyze the Behavior After 4°C
After reaching 4°C, if water is heated further, its density will start to decrease, which means the volume will begin to increase.

**Hint:** Consider what happens to the molecular arrangement of water as it continues to heat beyond 4°C.

### Conclusion
Thus, the correct answer to the question is that the volume of water decreases as it is heated from 0°C to 4°C.

**Final Answer:** The volume of water decreases until it reaches 4°C.