AP Bio Properties of Water

What property of water allows it to be such a versatile solvent that it is often called the "universal solvent?"

• Purity

• Polarity

• High heat capacity

• Expansion upon freezing

Which of the following properties of water enables molecules to cling together as they move from the roots to the leaves of plants?

• Water expands as it freezes.
• Water is an excellent solvent.
• Water exhibits cohesive behavior.
• Water moderates temperature.

Tags

NGSS.HS-ESS2-5

Capillary action (water creeping up surfaces) is the result of adhesion. Which aspect of water is responsible for this?

• Nonpolar covalent bonds enable water to dissolve other substances.

• Polar covalent bonds join molecules of water to other substances.

• Hydrogen bonds form between water and another substance.

• Ionic bonds enable electrons to flow through water and into another substance.

Large bodies of water do not quickly fluctuate, or change, in temperature. Why?

• Water is a solvent.

• Water has a high specific heat.

• Water acts as a buffer.

• Water is non-polar.

Some insects can stand on the surface of calm water. Their feet push the surface of the water down slightly, but they do not break the surface. Why?

• The insects are light enough so they do not break the hydrogen bonds holding the water molecules together
  
• The insects actually use their wings to hover slightly above the water’s surface and they only skim it with their feet.
• The insect’s feet are non-polar, so they are repelled by the polar water molecules and are pushed away from the water’s surface.
• The insects are small enough to see the individual water molecules, so they are able to step carefully from one molecule to the next
  

Tags

NGSS.MS-PS2-5

What term describes when water is attracted to other substances?

• Cohesion
• Adhesion
• Capillary Action
• Surface Tension

Why does water move from the roots to the leaves of plants?

• Water is pushed by little insects that work for the plant.

• Capillary action due to cohesion and adhesion pulls the water molecules like a chain.

• Water is pulled upward by gravity.

• Water heats up in the roots and vapor rises to the leaves.

Tags

NGSS.MS-ESS2-4

Attractions between water molecules due to polarity are called:

• Covalent bonds
• Ionic bonds
• Polar bonds
• Hydrogen bonds

Attraction of molecules to the same kind of molecule is called:

• adhesion

• capillary action

• cohesion

• surface tension

Why does ice float?

• As water freezes, it expands and its density decreases.
• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.
• As water freezes, air becomes trapped between the hydrogen bonds of water molecules.
• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.