For you scientists...

[Cali Coug]

When you burn wood, where does the weight go? The ashes are almost weightless in comparison to the wood.

Is the heat/energy released from the burn the cause for the weight reduction? You wouldn't think it could account for such a dramatic loss in the weight.

Yes, I realize I am an idiot.

[ute4ever]

You are not an idiot. You are an infamous amigo.

[YOhio]

Yeah, when you burn wood, why is it not stiff and solid anymore?

[woot]

This isn't even close to my field, but I imagine it has to do with wood being made of cellulose, and cellulose being made of carbon and oxygen (among other things, I assume). Heat causes the carbon and oxygen to be released in the forms of CO and CO2, and whatever is left remains as ashes. Since ashes are high in carbon, we can assume that there is more carbon in cellulose than there is oxygen.

Ok that sounds terrible but my chemistry is lacking (a problem I hope to fix eventually).

Upon further reflection, there are a lot of mistakes in the above. The oxygen and carbon necessary to "even out" the amount needed to make CO or CO2 are readily available in the air, so the carbon remaining is probably the result of a separate reaction, of which I know nothing. Meh.

[hyrum]

Originally Posted by Cali Coug

When you burn wood, where does the weight go? The ashes are almost weightless in comparison to the wood.

Is the heat/energy released from the burn the cause for the weight reduction? You wouldn't think it could account for such a dramatic loss in the weight.

Yes, I realize I am an idiot.

There is a lot of water that escapes as steam. Water weighs a lot. Don't forget all the particulates that leave in the smoke, and carbon as CO2. There is no mass that is converted to energy or else you would have a Hiroshima type event.

[Cali Coug]

Originally Posted by woot

This isn't even close to my field, but I imagine it has to do with wood being made of cellulose, and cellulose being made of carbon and oxygen (among other things, I assume). Heat causes the carbon and oxygen to be released in the forms of CO and CO2, and whatever is left remains as ashes. Since ashes are high in carbon, we can assume that there is more carbon in cellulose than there is oxygen.

Ok that sounds terrible but my chemistry is lacking (a problem I hope to fix eventually).

Upon further reflection, there are a lot of mistakes in the above. The oxygen and carbon necessary to "even out" the amount needed to make CO or CO2 are readily available in the air, so the carbon remaining is probably the result of a separate reaction, of which I know nothing. Meh.

I wouldn't think the oxygen would matter, since oxygen doesn't weigh very much. And the carbon is left behind (right?). Is it just the mass escaping as smoke like Hyrum notes? Surprising that so much escapes. You can have 100 lbs of wood reduced to just a few pounds of ashes. Is there really 95 pounds worth of chemicals that escape during the burn? That sounds like a lot.

[Cali Coug]

Originally Posted by ute4ever

You are not an idiot. You are an infamous amigo.

In-famous. That means more than famous.

[woot]

The water escaping is a good point, and it seems likely that much of the carbon in the cellulose goes up in the smoke, since wood can burn in the absence of CO, but not in the absence of O2.

I'm sure I could find a nice summary of this on the 'tubes in less time than it takes for all this speculation. Maybe I'll get around to it eventually.

[MikeWaters]

Woot, I think he asked that scientists answer the question. That's a hint he doesn't want to hear from you.

[woot]

Originally Posted by MikeWaters

Woot, I think he asked that scientists answer the question. That's a hint he doesn't want to hear from you.

Do you have a crush on me? 'Cause I'm not available. It's funny how anxious you are to turn so many threads on your own board into childish pissing.