ap bio test three review
what are the four emergent properties of water that are important for life?
-cohesion -moderation of temperature -expansion upon freezing -solvent properties
what is the concentration of hydroxide ions in a solution where ph = 10
1 x 10^-4
A solution at pH 6 contains __________ than the same amount of solution at pH 8. (Concept 3.3)
100 times more H+
what is the concentration of hydroxide ion sin a solution of ph 5
10^-9
What are nonpolar molecules that cluster away from water molecules called? (Concept 3.2)
Hydrophobic
water shows high cohesion and surface tension and can absorb large amounts of heat because of large numbers of which type of bonds between water molecules?
hydrogen bonds
A molecule that has all nonpolar covalent bonds would be __________. (Concept 3.2)
hydrophobic
Sweating has a cooling effect because of water's high __________. (Concept 3.2)
heat of vaporization
The reason that coastal climates are more moderate than inland climates primarily water's high __________. (Concept 3.2)
specific heat
What do cohesion, surface tension, and adhesion have in common with reference to water? (Concept 3.2)
All are properties related to hydrogen bonding.
Cells are surrounded by water, with which they are mostly filled. Which of the following occurs as a result? (Concept 3.1)
All of the listed responses are correct.
How does the polarity of water contribute to its ability to dissolve so many substances? (Concept 3.2)
Because it is polar, water's negatively charged oxygen atoms and positively charged hydrogen atoms are attracted to positively and negatively charged ions and molecules.
Which of the following dissociations is that of an acid? (Concept 3.3)
HF → H+ + F-
Which of the following accurately relates the emergent properties of water to the effects of global warming in the Arctic? (Concept 3.2)
Ice floats because it is less dense than liquid water; floating ice insulates water below and provides a habitat for some species. The significant increase in Arctic air temperature over the past 50 years is causing a reduction in sea ice, compromising these beneficial effects of sea ice.
Which of the following occurs because molecules of water are farther apart in ice than in liquid water? (Concept 3.2)
Ice floats.
Why are cell membranes composed primarily of hydrophobic molecules? (Concept 3.2)
In order to perform their function of separating the aqueous solutions outside cells from the aqueous solutions inside cells, cell membranes cannot be soluble in water.
You can fill a glass of water to just slightly above the rim without the water spilling over the glass. What property of water best explains this phenomenon? (Concept 3.2)
Surface tension
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? (Concept 3.2)
Systems for temperature regulation would have to be much more efficient.
Water is a polar molecule. What does this statement mean? (Concept 3.1)
That atoms in the molecule have partial charges as a result of unequal sharing of electrons in a covalent bond
Adhesion is best described as which of the following? (Concept 3.2)
The clinging of one substance to another substance
The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as __________. (Concept 3.2)
The heat of vaporization of that substance
In a group of water molecules, hydrogen bonds form between which of the following? (Concept 3.1)
The oxygen atom in one water molecule and a hydrogen atom in another water molecule
skin is coated with a hydrophobic glycolipid. what would happen if this glycolipid were not present?
a and b only
An acid is __________. (Concept 3.3)
a compound that donates hydrogen ions to a solution
water has an unusually high specific heat. what does this mean?
a large amount of heat is required to raise the temperature of water.
if water was treated with molecules that reduce or remove surface tension, which of the following would occur?
all of the above would occur
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 __________. (Concept 3.2)
both caused by water's partial charges
A substance that minimizes changes in the concentration of H+ and OH- in a solution is a __________. (Concept 3.3)
buffer
The phenomenon responsible for maintaining the upward movement of water through vessels in a tree is __________. (Concept 3.2)
cohesion
Adding acid tends to __________ of a solution. (Concept 3.3)
increase the hydrogen ion concentration and lower the pH
The tendency of water molecules to stay close to each other as a result of hydrogen bonding __________. (Concept 3.2)
is called cohesion, acts to moderate temperature, provides the surface tension that allows small animals to move across a water surface, and helps to keep water moving through the vessels in a tree trunk
Adding a base tends to __________ of a solution. (Concept 3.3)
lower the hydrogen ion concentration and increase the pH
Water is a very versatile solvent because water molecules are __________. (Concept 3.2)
polar
A glass of grapefruit juice, at pH 3, contains __________ H+ as a glass of tomato juice, at pH 4. (Concept 3.3)
ten times as much
The amount of heat required to change the temperature of 1 g of any substance by 1°C is defined as __________. (Concept 3.2)
the specific heat of that substance
The partial charges on a water molecule occur because of __________. (Concept 3.1)
the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
in a glass of old-fashioned lemonade, what is the solvent?
water