Q24E
Question
As stated in the text, convincing examples that demonstrate the law of conservation of matter outside of the laboratory are few and far between. Indicate whether the mass would increase, decrease, or stay the same for the following scenarios where chemical reactions take place:
(a) Exactly one pound of bread dough is placed in a baking tin. The dough is cooked in an oven at 350 °F releasing a wonderful aroma of freshly baked bread during the cooking process. Is the mass of the baked loaf less than, greater than, or the same as the one pound of original dough? Explain.
(b) When magnesium burns in air a white flaky ash of magnesium oxide is produced. Is the mass of magnesium oxide less than, greater than, or the same as the original piece of magnesium? Explain.
(c) Antoine Lavoisier, the French scientist credited with first stating the law of conservation of matter, heated a mixture of tin and air in a sealed flask to produce tin oxide. Did the mass of the sealed flask and contents decrease, increase, or remain the same after the heating?
Step-by-Step Solution
Verified- The mass of dough would decrease.
- The mass of magnesium oxide would be greater than the original piece of Magnesium.
- The mass inside the steel flask remains the same.
Heating the dough makes the moisture evaporates from it. So, the mass of dough decreases.
When Magnesium is burned in the air, it combines with oxygen resulting in an increase in mass.
By applying the law of conservation of mass, mass remains constant inside the flask.