Pls HeLP me in Chemistry about Law of Conservation of Matter!!!!?

Question

When you burn a log in the fireplace, the resulting ashes have a mass less than that of original log. Account for the difference in the mass.

HELP!

Answer 1

The reason that ashes have a mass less than that of original log is because when you burn a log in the fireplace, a chemical reaction takes place.  The wood in the log is primarily cellulose, and organic compound made up of carbon, hydrogen and oxygen.  It reacts with oxygen during burning and forms primarily two new compounds, carbon dioxide and water vapor, both of which are gases that escape into the air.  What is left, are substances in the wood that did not burn.  They do not represent  the mass of the wood that got converted to carbon dioxide and water.  Therefore what is left weighs less than the original log.

Answer 2

when you burn a log of wood it is a chemical change i.e it is irreversible during the process in a chemical way the log reacted with o2 and the products are co2,soot,ashes,etc which cannot be obtained back because it is done in an open system that's the reason why the mass can't be thwe same

  

Answer 3

My science teacher is the crappiest science teacher ever. she does the worst explaining ever and chemistry is her strength and yet she is still sucky. All i know (not from her) is that the Law of Conservation fo Mass or matter is that matter cannot be gained or lossed. That means, nothing can just be created. A classic example is a candle. You light up a candle and put it in a jar and seal it. It will burn and nothing can escape. There is the melted candle wax and the carbon dioxide inside the jar. The total mass of the carbon dioxide and the candle wax is the same as what it was before. in your example with the ashes. the ashes will weight less because the carbon dioxide that has been released is in the air somewhere.

Answer 4

Simply, as the log burns it forms ash but it also forms a lot of carbon dioxide gas which escapes into the air. The loss od this gas means that the final mass of the ash is less than the mass of the log and the oxygen used to burn it.

To show the Law of Conservation of Mass (or Matter) you would have to burn the log in a sealed container with a know mass of oxygen. You would weigh the container at the start and again after burning the log. The mass would not have changed.

Simply  Mass of reactants = Mass of Products

Hopr this helps clear things up for you.

Answer 5

The Law of Conservation of mass dictates that mass is neither created nor destroyed. The log has also been turned into carbon dioxide, as well as other chemicals.