Boiling water is changing into steam. Under this condition the specific heat of water is

Options

A. zero
B. one
C. infinite
D. less the one

Explanation

To solve the question regarding the specific heat of boiling water changing into steam, we can follow these steps:

### Step 1: Understand the Concept of Specific Heat
Specific heat capacity (S) is defined as the amount of heat (Q) required to raise the temperature of 1 kg of a substance by 1 Kelvin (or 1°C). The formula for specific heat is given by:
\[ S = \frac{Q}{m \Delta T} \]
where:
- \( S \) = specific heat capacity
- \( Q \) = heat added or removed
- \( m \) = mass of the substance
- \( \Delta T \) = change in temperature

### Step 2: Analyze the Situation
In the case of boiling water, the water is at its boiling point (100°C at standard atmospheric pressure). When water is boiling and changing into steam, it is undergoing a phase change from liquid to gas. During this process, the temperature of the water does not change despite the addition of heat.

### Step 3: Determine the Change in Temperature
Since the water is boiling, the temperature remains constant at the boiling point. Therefore, the change in temperature (\( \Delta T \)) is:
\[ \Delta T = 0 \]

### Step 4: Substitute into the Specific Heat Formula
Substituting \( \Delta T = 0 \) into the specific heat formula:
\[ S = \frac{Q}{m \cdot 0} \]

### Step 5: Analyze the Result
In this equation, since \( \Delta T \) is in the denominator, we encounter a division by zero. Mathematically, this leads to:
\[ S \rightarrow \infty \]
This indicates that the specific heat capacity of water during the boiling process is infinite.

### Conclusion
Thus, the specific heat of water when it is boiling and changing into steam is infinite.

### Final Answer
The specific heat of boiling water is infinite.

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