Answer:
The law of conservation of mass was obeyed since some of the mass evaporated while the cookies were baking.
Explanation:
Maria mixes water, flour, sugar, baking powder, butter and chocolate chips and then measures the mass of her ingredients.
Initial mass of ingredients = 1053 g
Final mass = 845 g
All these information are not of any great help.
Law of conservation of mass states that:
For any system closed to all transfers of matter and energy, the mass of the system can not change with respect to time, as system's mass cannot change, any mass can neither be added nor be removed.
In this process of baking, considering the cookies as our system, they never formed a closed system. Hence were free for evaporation.
During the process of baking, water from dough must have evaporated and mass must have reduced.
Hence, the law of conservation of mass was not obeyed.