Which would cause a more serious burn 30g of steam or 30g of liquid water, both at `100^(@)C`, and why is this so ?

Options

A. Water, because it is denser than steam.
B. Steam, because of its specific heat capacity.
C. Steam, because o fits latent heat of vaporization.
D. Water, because its specific heat its greater than that of steam.

Answer

To determine which would cause a more serious burn between 30g of steam and 30g of liquid water, both at 100°C, we need to analyze the energy content of both substances.

### Step-by-Step Solution:

1. **Understanding the State of Matter**:
- At 100°C, water exists in two states: liquid water and steam (water vapor). Both are at the same temperature, but they have different physical properties.

2. **Latent Heat of Vaporization**:
- When water changes from liquid to steam, it absorbs heat without a change in temperature. This heat is known as the latent heat of vaporization. For water, the latent heat of vaporization is approximately 2260 J/g.

3. **Calculating the Total Energy**:
- For 30g of steam at 100°C, the total energy content due to the latent heat is:
\[ \text{Energy in steam} = \text{mass} \times \text{latent heat} = 30\,g \times 2260\,J/g = 67800\,J \]
- For 30g of liquid water at 100°C, since it is already in the liquid state, it does not contain this additional energy. The energy content is primarily due to its temperature, but it does not have the latent heat associated with vaporization.

4. **Comparison of Energy Content**:
- The steam has a significantly higher energy content (67800 J) compared to the liquid water (which has no additional energy from latent heat). This means that when steam comes into contact with skin, it will release this latent heat as it condenses back into water, causing a more severe burn.

5. **Conclusion**:
- Therefore, 30g of steam at 100°C would cause a more serious burn than 30g of liquid water at the same temperature because of the additional energy released during the condensation of steam.

### Final Answer:
30g of steam at 100°C would cause a more serious burn than 30g of liquid water at the same temperature because steam contains latent heat of vaporization, which releases a significant amount of energy upon condensing.

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