After a fire, the ashes have less mass and take up less space than the trees and vegetation before the fire. How can this be explained in terms of the Law of Conservation of Mass?
2006-09-19 15:38:28 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
While the idea that mass and energy are interchangeable, JohnTAdams' answer is completely off the mark. Chemical reactions NEVER involve a change in mass. The amount of energy involved in a chemical reaction, even one as violent as burning wood, cannot and does not account for why ashes weigh less than the starting material. If you did your experiment in a closed environment, one where you weighed all the gases involved in the burning, the mass WOULD be the same before and after the chemical reaction.
2006-09-19 15:49:33 · answer #1 · answered by metatron 4 · 1⤊ 0⤋
When you burn some stuff(woods, vegetation etc) you are left with ashes and surely ashes have less mass than the meterial burnt but law of conservation of mass still holds. Actually you have overlooked the CO2 gas escaped in the air. If you could catch and bring that gas back and weigh it with the ashes, you will have exactly the same mass of the original material.
Definitely gas can't be caught. Therefore if you burn something in an airtight container and put it on a scale. There will be no change in mass while the combustion will be in progress because CO2 and water vapours released could not escape.
2006-09-19 15:49:55 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Some of the material that was getting burned went away as smoke. So the total amount of mass in the entire world stays the same, some of it just went somewhere else.
As a matter of fact, though, if you burn things for just the right amount of time, you can actually get the mass to INCREASE. Again, this does not violate conservation of mass, it's just that oxygen is being added to the material you're burning.
2006-09-19 15:39:28 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Mass and energy are interchangeable.
And any given amount of mass contains a large amount of energy.
You can't create or destroy mass, but you can change it into energy. That's how atom bombs work, for example. A small amount of mass is converted into a large amount of energy, and you have a huge explosion.
When there's a fire, some of the burned material is left behind as ashes. Some becomes the particles you see as smoke and drifts away. The rest becomes energy -- heat.
The mass hasn't disappeared, it's just become the other half of the mass/energy equation.
2006-09-19 15:44:27 · answer #4 · answered by johntadams3 5 · 0⤊ 1⤋
The "missing" mass was turned to smoke or converted to energy in the form of light and heat. Most people forget that the law allows for matter-energy conversion. And volume has no relationship to conservation of mass.
2006-09-19 15:41:10 · answer #5 · answered by juicy_wishun 6 · 0⤊ 0⤋
law of conservation of mass states that mass of reactatnts is equal to mass of products
tom
2006-09-19 15:47:01 · answer #6 · answered by remo 2 · 0⤊ 0⤋
Think smoke.
Significant amounts of carbon, nitrogen, and hydrogen go from carbohydrate to gas, and dissappear in clouds.
2006-09-19 15:40:43 · answer #7 · answered by Curly 6 · 1⤊ 0⤋
the application of the fire causes the mass of the trees and vegetation to separate and breakdown into gases and lighter than air particles that are transported away as smoke.
2006-09-19 15:47:46 · answer #8 · answered by Cynic 2 · 0⤊ 0⤋
The majority of the carbon that once constituted the tree gets turned into carbon dioxide during the burning process and leaves with the smoke.
2006-09-19 15:43:19 · answer #9 · answered by bruinfan 7 · 0⤊ 0⤋
Ashes are carbon, and the other components (mostly Hydrogen, Oxygen and Nitrogen) are gases that are liberated into the atmosphere.
2006-09-19 16:22:05 · answer #10 · answered by universalsoul 2 · 0⤊ 0⤋