Final answer:
The Law of Conservation of Mass states that mass remains constant in a closed system, such as when wood burns and transforms into ash, carbon dioxide, and water vapor. The initial mass of wood equals the mass of the ash and the gaseous byproducts, even though the wood appears to be 'lost.' This is a fundamental concept in chemistry that also relates to energy transformations during combustion.
Step-by-step explanation:
When 400 grams of wood are burned and 30 grams of ash remain, this demonstrates the Law of Conservation of Mass. Despite the appearance that matter is being destroyed during combustion, in reality, the mass remains constant. The wood that has been burned combines with oxygen resulting in ash, carbon dioxide, and water vapor.
These gases are released into the atmosphere and are not easily visible. Thus, the 'lost' mass from the initial 400 grams of wood is actually transformed into gaseous byproducts that, if measured along with the oxygen consumed during burning, would add up to the original mass of the wood.
The temperature of burning wood is an intensive property and is relatively consistent whether for a match or a bonfire. However, the amount of heat produced is an extensive property and varies with the amount of wood.
This principle is essential for understanding chemical reactions and energy transformations. For instance, the amount of energy released from the wood can be quantified, indicating that each gram of wood, when burned, produces about 16 kJ (or 4 kcal) of energy, which translates to a power output of 4 kW when one gram is burned every 4 seconds.