Chapter 2.4: Water: A Vital Compound Flashcards
Define hydrogen bonding
o Hydrogen Bonds- a weak association formed with hydrogen in polar covalent bonds. The partially positive hydrogen is attracted to partially negative atoms in polar covalent bonds. In water, oxygen and hydrogen in different water molecules form hydrogen bonds.
What is a weak association formed with hydrogen in polar covalent bonds?
hydrogen bonds
Define surface tension
• Surface Tension- a tautness of the surface of a liquid, caused by the cohesion of the molecules of liquid
What is a tautness of the surface of a liquid, caused by the cohesion of the molecules of liquid?
surface tension
Explain the water property of cohesion
Hydrogen bonds hold water molecules together
Explain the water property of high specific heat
Hydrogen bonds absorb heat when they break and release heat when they form minimizing temperature changes
Explain the water property of high heat of vaporization
Many hydrogen bonds must be broken for water to evaporate
Explain the water property of lower density of ice
Water molecules in an ice crystal are spaced relatively far apart because of hydrogen bonding
Explain the water property of solubility
Polar water molecules are attracted to ions and polar compounds, making these compounds soluble
What is an example of the cohesion property of water?
Leaves pull upward from the roots; seeds swell and germinate
What is an example of the high specific heat property of water?
Water stabilizes the temperature of organisms and the environment
What is an example of the high heat of vaporization property of water?
Evaporation of water cools body surfaces
What is an example of the lower density of ice property of water?
Because ice is less dense than water, lakes do not freeze solid allowing fish and other life in lakes to survive the winter
What is an example of the solubility property of water?
Many kinds of molecules can move freely in cells, permitting a diverse array of chemical reactions
What is adhesion in terms of water molecules?
o The polarity of water causes it to be attracted to other polar molecules as well (adhesion). Water adheres to any substance with which it can form hydrogen bonds.
