For a fixed mass of water, at what temperature will the volume become least?

Options

A. `0^(@)C`
B. `4^(@)C`
C. `54^(@)C`
D. `100^(@)C`

Explanation

To determine the temperature at which the volume of a fixed mass of water becomes least, we need to understand the concept of anomalous expansion of water. Here’s a step-by-step solution:

### Step 1: Understand Anomalous Expansion
Water is unique because it exhibits anomalous expansion. This means that, unlike most substances, water does not continuously expand as it is heated. Instead, it contracts to a certain temperature and then begins to expand.

**Hint:** Remember that most substances expand when heated, but water behaves differently in a specific temperature range.

### Step 2: Identify the Temperature Range
When we consider the temperature range for water, we note that at 0 degrees Celsius (the freezing point), water starts as ice and has a certain volume. As the temperature increases from 0 degrees Celsius, the volume of water decreases until it reaches a minimum at a specific temperature.

**Hint:** Think about the freezing point of water and how it behaves as it warms up.

### Step 3: Determine the Minimum Volume Temperature
The minimum volume of water occurs at 4 degrees Celsius. This is the temperature at which water reaches its maximum density, and any further increase in temperature will cause the volume to increase again.

**Hint:** Recall that the maximum density of water corresponds to the minimum volume.

### Step 4: Conclusion
Thus, for a fixed mass of water, the temperature at which the volume becomes least is **4 degrees Celsius**.

**Final Answer:** The volume of a fixed mass of water is least at **4 degrees Celsius**.