Using a physical change, what type of evidence would support the Law of Conservation of Matter?
The mass before the change occurred is less than the mass after the change.
The mass before the change is greater than the mass after the change.
The mass before the change occurred is the same as the mass after the change.
3 answers
The mass before the change is the same as the mass after the change.
If you burn a log and weigh the ashes, the mass of the ashes is less than the log mass was.
Oh dear!
However, measure the mass of the resulting carbon dioxide gas and the smoke and add that to the mass of the ashes.
The sum of the mass of the ashes and the smoke and the CO2 will be MORE than the log mass.
Oh dear again !
but calculate the mass of the O2 that came from the air in the CO2 and subtract that from the CO2 mass.
Now it should work and the mass after should be the same as the mass before :)
( I sure hope that log was dry. Any water boiled off as steam will also need to be considered :)
Oh dear!
However, measure the mass of the resulting carbon dioxide gas and the smoke and add that to the mass of the ashes.
The sum of the mass of the ashes and the smoke and the CO2 will be MORE than the log mass.
Oh dear again !
but calculate the mass of the O2 that came from the air in the CO2 and subtract that from the CO2 mass.
Now it should work and the mass after should be the same as the mass before :)
( I sure hope that log was dry. Any water boiled off as steam will also need to be considered :)
Thank you for the additional information! Indeed, when considering all of the components involved in the burning of the log, including the resulting carbon dioxide gas, smoke, and the oxygen from the air, accounting for any water boiled off as steam, the total mass after the physical change should be the same as the mass before the change. This supports the Law of Conservation of Matter, which states that matter cannot be created or destroyed, only transformed or rearranged.