AP Biology Chapter: 3 Water and Life
We can be sure that a mole of table sugar and a mole of vitamin C are equal in their
# of molecules
Which of the following is possible due to the high surface tension of water?
A water strider can walk across the surface of a small pond
The bonds that are broken when water vaporizes are
Hydrogen bonds between water molecules
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
unit of energy equal to .239 cal is a
Joule
The energy of motion is
Kinetic energy
The number of moles of solute per liter of solution determines the
Molarity
The amount represented by 6.02 x 10^23 molecules is a(n)
Mole
Hydrophobic substances such as vegetable oil are
Nonpolar substances that repel water molecules
When atmosphere CO2 dissolves in seawater, it reacts with water to form carbonic acid, which causes
Ocean precipitation
Hydrogen ion concentration of a solution will determine the
Ph
In a molecule of water, the oxygen atom does not share electrons equally with the two hydrogen atoms. This results in ____________________ between the atoms of this molecule.
Polar covalent Bond
In a single molecule of water, the two hydrogen atoms are bonded to the single oxygen atom by
Polar covalent bonds
Which of the following is not an emergent property of water: a. Moderation of temperature b. Less dense in its solid state c. Polar covalent molecules d. Cohesion e. Versatilty as a solvent
Polar covalent molecules
The substance that is dissolved in a solution is the
Solute
When liquid is a homogenous mixture with at least two substances it is called a(n)
Solution
The dissolving agent of a solution is the
Solvent
A liquid with a relatively high specific heat and heat of vaporization is
Water
It requires 1 calorie of heat to raise the temperature of _____________ by 1 degree C.
Water
One _____________ is the amount of heat required to raise the temperature of 1 g of water by 1 degree C .
Calorie
Hydrogen bonds can hold the atoms of a substance together. This phenomenon is known as*
Cohesion
What property of water is responsible for water transport in plants?
Cohesion
Some substances that are too large to dissolve in water will remain suspended in the water forming a(n
Colloid
What determines the cohesiveness of water molecules
Hydrogen bonds
A substance that reduces the hydrogen ion concentration of a solution, for example NH3
Base
Ice is lighter and floats in water because it is a crystalline structure in which each water molecule is bonded to a maximum of four other water molecules by which kind of bonds?
Hydrogen bonds
_________________ occurs due to the fact that the "hottest" molecules, or the ones with the most kinetic energy, are leaving the surface as a gas.
Evaporation cooling
Which of the following solutions has the greatest concentration of hydrogen ions (H+)?
Gastric juice at pH 2
A measure of matter's total kinetic energy due to motion of its molecules is
Heat
The amount of heat 1 gram of a liquid must absorb to become a gas is known as
Heat vaporization
When a substance such as salt is dissolved in water, the ions will separate and become surrounded by water molecules creating a(n
Hydration Shell
Water molecules stay close to each other due to the attraction of the slightly positive hydrogen atoms of one molecule and the slightly negative oxygen atom of a different molecule. This attraction is also known as
Hydrogen bonding
A substance that increases the hydrogen ion concentration of a solution, for example HCl
Acid
When one substance clings to another, such as water molecules clinging to the cell walls of water conducting cells in a plant, _______________ is occurring.
Adhesion
Which bonds must be broken for water to vaporize?
Hydrogen bonds
H+
Hydrogen ion
H3O+
Hydronium ion
A substance with an affinity for water is said to be*
Hydrophilic
A substance with no affinity for water, that is nonionic and nonpolar is said to be
Hydrophobic
OH-
Hydroxide ion
An example of a hydrogen bond is the bond between*
The H of one water molecule and the O of another water molecule
Many mammals control their body temperatures by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
The absorption of heat by the breaking of hydrogen bonds
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1L of a solution of pH 6?
10,000 more
One liter of a solution pH 9 has how many more hydroxide ions (OH-) than 1L of a solution of pH 4?
100,000 times more
How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution?
6.02x 10^23
When water is the solvent the solution is a
Aqueous solution
A substance that minimizes changes in the concentration of hydrogen ions and hydroxide ions in a solution is a(n
Buffer
A measure of heat intensity that represents the average kinetic energy of the molecules, regardless of the volume of the matter, is
Temperature
The ______________________ for any substance is defined by the amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature by 1oC
Specific heat
________________ is the measure of how difficult it is to stretch or break the surface of a liquid.
Surface tension
Water is able to form hydrogen bonds because *
The bonds that hold together the atoms in a water molecule are polar covalent
The formation of ice during colder weather helps moderate the seasonal transition to winter. This is mainly because
The formation of hydrogen bonds releases heat
Which of the following statements is true about buffer solutions
They maintain a relatively constant pH
Which of the following is a hydrophobic material?
Wax