Properties of water (polarity, cohesion, adhesion, heat capacity) Knowledge-Based Practice

Questions

1. 1.

   Why does liquid water require a relatively large amount of heat energy to increase its temperature compared to most other liquids of comparable molecular mass?

   • A) Covalent bonds within the water molecules must be broken before their average kinetic energy can increase.
   • B) A large portion of the absorbed energy is used to break hydrogen bonds between molecules before their kinetic energy rises.
   • C) Water molecules dissociate spontaneously into hydronium and hydroxide ions, which absorbs the majority of the thermal energy.
   • D) Strong adhesive forces between water molecules and container walls prevent molecular movement.
2. 2.

   Water is recognized as a versatile biological solvent capable of dissolving many ionic and polar substances. Which fundamental property of the water molecule directly accounts for its ability to form hydration shells around charged ions?

   • A) The nonpolar nature of the bonds between oxygen and hydrogen atoms
   • B) The molecular dipole resulting from unequal electron sharing between oxygen and hydrogen
   • C) The lower density of solid ice compared to liquid water
   • D) The formation of irreversible covalent bonds between water and solute particles
3. 3.

   Certain small organisms, such as water striders, can walk across the undisturbed surface of a pond without breaking through. Which property of water, resulting from intermolecular hydrogen bonding between water molecules, directly enables this behavior?

   • A) Evaporative cooling
   • B) Adhesion to nonpolar surfaces
   • C) Decreased density in the solid state
   • D) Cohesion producing high surface tension
4. 4.

   During water transport in vascular plants, water molecules form hydrogen bonds with the polar cellulose fibers of xylem cell walls. Which property of water is directly responsible for this attraction to a different polar surface?

   • A) High specific heat
   • B) Cohesion
   • C) Low density in the solid state
   • D) Adhesion
5. 5.

   Which property of water is primarily responsible for buffering temperature changes in aquatic ecosystems and coastal climates?

   • A) High surface tension generated by cohesive forces between molecules
   • B) Strong capillary action driven by adhesive forces to polar surfaces
   • C) High specific heat capacity resulting from extensive hydrogen bonding
   • D) Lower density of the solid crystalline lattice compared to liquid water

Answers and step-by-step solutions appear after you finish the test.