keywords:
Bookmark and Share



Front Back
1) Cells are surrounded by water, and cells themselves consist of about 70% to 95% water. As a result _____.
(all of the above)

the temperature of living things tends to change relatively slowly a variety of nutrient molecules are readily available as dissolved solutes waste products produced by cell metabolism can be easily removed dissolved substances can be easily transported within a cell or between cells in multicellular organisms
2) Water is a polar molecule. This means that _____.
the opposite ends of the molecule have opposite electrical charges
3) The partial charges on a water molecule occur because of _____.
the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
4) In a group of water molecules, hydrogen bonds form between _____.
the oxygen atom in one water molecule and a hydrogen atom in another water molecule
5) The tendency of water molecules to stay close to each other as a result of hydrogen bonding _____
(all of the above)
provides the surface tension that allows leaves to float on water is called cohesion keeps water moving through the vessels in a tree trunk acts to moderate temperature
6) What do cohesion, surface tension, and adhesion have in common with reference to water?
All are properties related to hydrogen bonding.
7) Most of water's unique features (for example, its versatility as a solvent, ability to moderate temperature, and cohesive behavior) result from the fact that _____.
oxygen attracts electrons more than hydrogen does
8) The ability of water molecules to form hydrogen bonds with other water molecules and water's ability to dissolve substances that have charges or partial charges are _____.
both caused by water's partial charges
9) The phenomenon responsible for the maintenance of a column of water as it moves upward through a vessel is _____.
cohesion
10) Adhesion is best described as _____.
the clinging of one substance to another substance
11)  You can fill a glass of water to just slightly above the rim without it spilling over the glass. What property of water best explains this phenomenon?
Surface tension
12) Which action would involve the greatest transfer of heat?
condensing 5 g of steam to liquid water
13) Imagine that organisms consisted of 70-95% alcohol instead of 70-95% water. Alcohol's specific heat is about half that of water. How would living things be different?
Systems for temperature regulation would have to be much more efficient.
14) The amount of heat required to change the temperature of 1 g of any substance by °C is defined as _____.
the specific heat of that substance
15) he amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as _____.
the heat of vaporization of that substance
16) The reason that coastal climates are more moderate than inland climates is due primarily to water's high _____.
specific heat
17) Sweating has a cooling effect because of water's high _____.
heat of vaporization
18) Water molecules have _____ than molecules of similar size, such as ammonia and methane.
a higher boiling point
19)Because molecules of water are farther apart in ice than in liquid water, _____.
ice floats
20)Water is a very versatile solvent because water molecules are_____.
polar
21) How does the polarity of water contribute to its ability to dissolve so many substances?
Because it is polar, water's oppositely charge ends are attracted to positively and negatively charged ions and molecules. Water molecules form a hydration shell around oppositely charged particles.
22) Nonpolar molecules that cluster away from water molecules are called _____ molecules.
hydrophobic
23) A molecule that has all nonpolar covalent bonds would be _____.
hydrophobic
24) Hydrophobic molecules are _____ water.
repelled by
25)Why are cell membranes composed primarily of hydrophobic molecules?
In order to perform their function of separating the aqueous solutions outside of cells from the aqueous solutions inside of cells, cell membranes cannot be soluble in water.
26)Hydrophilic substances, but not hydrophobic substances, _____.
have charges and partial charges to which water molecules can adhere
27) Some substances, such as oil and gasoline, will not dissolve in water because _____.
their molecules have no charges or partial charges to which water molecules can adhere
28) Sucrose has a molecular mass of 342 daltons. To make a 2-molar (2 M) solution of sucrose, _____
stir 342 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 0.5 L
29) A mole of ethyl alcohol weighs 46 g. How many grams of ethyl alcohol are needed to produce 1 L of a 2-millimolar (2 mM) solution?
0.092 g
30) An acid is _____.
a compound that donates hydrogen ions to a solution
31) Adding acid tends to ____ of a solution.
increase the hydrogen ion concentration and lower the pH
32) Which of the following dissociations is that of an acid?
HF → H+ + F-
33) A glass of grapefruit juice, at pH 3, contains _____ H+ as a glass of tomato juice, at pH 4.
ten times as much
34) A solution at pH 6 contains ____ than the same amount of solution at pH 8
100 times more H+
35) Adding a base tends to _____ of a solution.
lower the hydrogen ion concentration and increase the pH
36) When the pH of a solution shifts from 7 to 3, how has the hydrogen ion concentration changed?
It has increased by 10,000 times.
37) Pure water has a pH of 7. Why does uncontaminated rainwater have a pH of 5.6?
formation of carbonic acid from carbon dioxide and water
38) A substance that minimizes changes in the concentration of H+ and OH- in a solution is a(n) ______.
Buffer
39) Why is the increasing amount of carbon dioxide being taken up by the oceans a cause for concern?
More carbon dioxide causes an increase in carbonic acid (H2CO3) which leads to a decrease in the concentration of carbonate ion (CO32-).
40) Which of the following statements is true about acid precipitation?
It washes away some minerals that are plant nutrients, while causing some toxic minerals to accumulate.
x of y cards