Answer:
A) The mass of the cup of frozen water is 12 grams which means the mass did not change.
Step-by-step explanation:
When the cup of water is placed in a sealed container in freezer overnight the mass of the cup along with water will not change because the system is closed as well as the water present in it is not allowed to evaporating as the rate of evaporation decreases on low temperatures.
Secondly when he takes out the cup from the container he found that the cup has cracked on its sides. This has happened because when the liquid freezes, it starts to form from top because the ice has lower density and hence floats on surface. When the surface is blocked by ice, the inner liquid when freezes results in volume increases therefore, it cracks the glass.
With respect to water it is found then when eater is cooled its density first starts to increases but when it reached around 4 °C it starts forming solid ice which results in the formation of hollow spaces and hence, increases the volume by 9%.