BSC1010 -Chapter 3- Test Review

Hydrophobic

"water-fearing"; pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water.

Hydrophilic

"water-loving"; pertaining to polar or charged molecules (or parts of molecules) that are soluble in water

Water's high specific heat is mainly a consequence of the...? -the small size of the water molecules -high specific heat of oxygen and hydrogen atoms -absorption and release of heat when hydrogen bonds break and form -fact that water is a poor heat conductor -the inability of water to dissipate heat into dry air

-absorption and release of heat when hydrogen bonds break and form

Why does water display unique properties like cohesion, heat capacity, and making ice float? -because of the covalent bonds between the oxygen and hydrogen -because of its ability to hydrogen bond -because of its ability to make and break ionic bonds -because the electrons are shared equally between the oxygen and hydrogen atoms

-because of its ability to hydrogen bond

What property of water is responsible for water transport upward in plants? -moderation of temperature -insulation -its versatility as a solvent -cohesion and adhesion -its role as a buffer

-cohesion and adhesion

Which of the following phenomena is most likely due to the high cohesiveness of water? -lakes and rivers freeze from the top down, not the bottom up -the "Jesus lizard" can run across the surface of liquid water for short distances -adding salt to snow makes it melt -the temperature of Santa Monica Bay fluctuates less than the air temperature throughout the year -all of the above due to the cohesiveness of water

-the "Jesus lizard" can run across the surface of liquid water for short distances

Which of the following statements is true about buffer solutions? -they maintain a constant pH when bases are added to them but not when acids are added to them -they maintain a constant pH when acids are added to them but not when bases are added to them -they maintain a constant pH of exactly 7 in all living cells and biological fluids -they maintain a relatively constant pH -They are found in only living systems and biological fluids

-they maintain a relatively constant pH

A solution of pH 3 is 100 times more acidic than a solution of pH 5. -true -false

-true

At what temperature is water the most dense?

4°C

polar

Molecule with partial charges. Mixes with water; regions at the surface of the micelle

base

a compound that produces hydroxide ions and decreases hydrogen ion concentration in a solution

Non-polar

a molecule in which all atoms have the same electronegativity and the electron distribution is equal; doesn't mix with water; regions at the interior of the micelle

amphipathic

a molecule that has both a hydrophilic region and a hydrophobic region.

adhesion

an attraction between molecules of different substances

cohesion

an attraction between molecules of the same substance

acid

compound that forms hydrogen ions (H+) in solution

base pH

greater than 7

Why can water moderate temperature?

hydrogen bonds can tolerate changes in temperature

Why does ice float in liquid water?

hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.

charged molecules

ions; polar molecules are partially charged

Acid pH

less than 7

Why does water have a high specific heat?

much of the added energy is required to break hydrogen bonds.

Anions

negatively charged ions

Cations

positively charged ions

example of cohesion

surface tension

example of adhesion

water and plant cell walls

Buffers

weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH