Question

Which of the following does NOT show the law of conservation of mass?

A. 24 g of Mg burn in 32 g O2 to produce 56 g of MgO.

B. 24 mL of Mg burn in 32 mL O2 to produce 56 mL of MgO.

C. 2 atoms of Mg react with 1 molecule of O2 to produce 2 units of MgO.

D. 1 atom of Mg reacts with 1 atom of O to produce a unit of MgO that contains 2 atoms.

Answer 1

B .........completely burning anything usually results in carbon being produced there for any gases such as oxygen which make up the molecule would be destroyed or recombined...since I know nothing about the environment in which it is burning such as open or closed vessel this suffices the question in assuming some mass would be lost as gases and/or not be part of the new molecule.

Answer 2

Thank you !

Answer 3

A could also be the answer since oxygen is measured as a fluid and not grams. I don't know if they want you to answer with the question that is syntactically incorrect or the scientific one....I will stay with B and assume this isn't a english lesson or the "tell me which one is incorrect wording" I so disagree with our teaching system that shows you the wrong answer to a question

It should be about lets see who is paying attention it should be about who is retaining information and there are way better ways of showing you that without showing you the wrong answer to stuff what if you have a strong emotional reaction to the wrong answer and you retain the wrong answer in your long term memory......:( foolish teaching in my opnion