A sealed flask containing of liquid water is placed in a freezer
CHEMISTRY · Single correct · CBSE · Chemistry · Matter in Our Surroundings · Matter in Our Surroundings
Problem
A sealed flask containing 50mL of liquid water is placed in a freezer. After one hour, the contents are completely solid, and no mass has been gained or lost.
Which statement BEST justifies the classification of the change that occurred in the flask?
(a) It is a chemical change because energy was released when the water froze, indicating an exothermic reaction.
(b) It is a physical change because the molecular composition H2O remained unchanged.
(c) It is a chemical change because new hydrogen bonds formed between water molecules as it solidified.
(d) It is a chemical change because the liquid water turned into a new substance, ice, with different properties.