Answer:
- <u><em>The law of conservation of mass was obeyed since some of the mass evaporated while the cookies were baking.</em></u>
Explanation:
The <em>law </em>of conservation of mass, as other physic's laws, is universal, meaning that it is obeyed in any circumstance, place, and time.
Thus, any explanation that asserts that the law of conservation of mass is not obeyed must be discarded.
Hence, first, second and fourth options are incorrect.
The law of conservation of mass states that during any physical or chemical process the mass of the substances can neither created nor destroyed; then, what happened that made the mass of the mixture of ingredients mixed by Maria (1053 g) were greater than the mass of the cookies baked for 15 minutes (845 g)?
One of the physical process that occurs when cooking, due to the increase of temperature, is the evaporation of water (besides the chemical reactions between the ingredients, some of which produce other gases).
The water in form of vapor (steam) will "escape" from the mass and the oven, so when the cookies are weighted they will weight less than the mixture, because the water was transformed from liquid state to gas state; i.e. some of the mass evaporated while the cookies were baking. Thus, the third choice is correct.
= 80 mmol K⁺