Changes of state at the particle level Transitional Reasoning Download PDF

Questions

1. 1.

   A student investigates what happens when a small sample of liquid ethanol in a sealed, flexible bag is submerged in a warm water bath. Within minutes, the liquid completely vaporizes, causing the bag to inflate to many times its initial volume while the total mass of the sealed system remains unchanged. Based on the particle model of matter, which statement best explains this observation?

   • A) The ethanol particles absorb thermal energy and expand, causing each individual particle to grow significantly larger in size.
   • B) The chemical bonds within the ethanol molecules break apart, creating a much larger total number of independent atoms.
   • C) The intermolecular forces between the ethanol particles strengthen, actively pushing them apart into fixed, distant locations.
   • D) The ethanol particles gain kinetic energy and overcome intermolecular attractions, spreading far apart with large empty spaces between them.