Physical changes and changes of state Transitional Reasoning Download PDF

Questions

1. 1.

   A student places identical 50 g samples of crushed ice at -10 °C into two separate sealed, rigid flasks, labeled Flask X and Flask Y. Flask X is heated until its contents completely convert to steam at 110 °C, whereas Flask Y is left at 25 °C until all the ice melts into liquid water. Based on these observations and the principles of phase changes, which statement correctly describes the changes that occurred inside the flasks?

   • A) In Flask X, the intramolecular covalent bonds between hydrogen and oxygen atoms were broken to form separate elemental gases.
   • B) The total mass inside Flask X decreased significantly because gaseous water particles occupy more volume and possess less mass than ice.
   • C) In Flask Y, the melting of ice was an exothermic chemical process that produced a substance with different chemical properties.
   • D) In both flasks, only the spacing and physical arrangement of the water molecules changed, while their chemical composition remained unaltered.