Science Question In my work book?

Question

A block of wood is paced in a sealed non-flammable container. The mass of the container plus the wood is 2kg. The wood is then burnt inside the sealed container and, after burning, the mass is still 2kg. When the container is opened, however, the mass of the container and wood has decreased. The experiment was repeated several times, always with the same result

Suggest a possible explanation for the decrease in mass.

Answer 1

When the wood burns it produces several gases, the 2 main ones will be CO (Carbon Monoxide) and CO2 (Carbon Dioxide).

When the container is opened the gases escape and therefore the loss in mass is then noticable.

Answer 2

I assume heat was applied to the container to burn the wood. During this process nothing is destroyed but is converted, the wood is converted into charcoal and gases, when the container is opened the gases escape, this will be the decrease in mass as gas has a mass too.

Hope this is helpful.

Answer 3

The wood burns giving out Carbon dioxide and water. Hence the mass decreases but when it is inside the seal and air tight container the substances formed doesn't escape. I appreciate your question.