A student measures 10.5 g of mercury(II) ox-?

A student measures 10.5 g of mercury(II) ox-


ide into an open test tube and heats it. The


heat causes the mercury(II) oxide to decom-


pose into mercury and oxygen. After reaction,


the student ¯nds the mass of the contents of


the tube to be 9.7 g. Which one of the follow-


ing describes these observations?


1. The decomposition of mercury(II) oxide


does not obey the Law of Conservation of


Mass.


2. 0.8 grams of oxygen gas escape from the


tube.


3. Heating destroys some mass.


4. There must be some pretty big errors as-


sociated with the student's measurements.

A student measures 10.5 g of mercury(II) ox-?
2.





Law of Conservation of Mass rules out 1 %26amp;3.