Bio180 smartbook quizzes
Which of the following contributes to water's stability in a liquid state
A high heat of fusion , a high heat of vaporization
When water ionizes, it produces what ions?
H+ and OH-
Polar covalent O-H bonds in water molecules enable hydrogen bonds to form between water molecules. Which of the following properties of water result from hydrogen bond formation?
High heat of vaporization Adhesion Surface tension Cohesion High specific heat
A base will absorb ________ ions in solution.
Hydrogen
Which types of chemical bonds are easily broken in water?
Hydrogen bonds , ionic bonds
Molecules are likely to dissolve easily in water if they contain which type(s) of bonds?
Ionic Bonds , Polar covalent bonds
A substance that releases hydrogen ions into solution is called a(n)
acid
If you add H+ ions to a solution, it becomes more
acidic
The ________ properties of water allow it to coat the digestive tract of animals.
adessive
A substance that absorbs hydrogen ions in solution is called a(n)
base
Properties of a solution that depend strictly on the total number of dissolved solutes, and not the specific type of solute, are called ________ properties.
colligative
Acid rain can _______ the pH of water entering the roots of plants
decrease
In ice, H2O molecules move ______ slowly than in water, and consequently hydrogen bonds are broken ______ frequently.
more , less
Water has a high heat of fusion. This means that:
much energy must be withdrawn to cause water to change from a liquid state to solid.
What type of bonds are most likely to be found in a hydrophobic molecule?
nonpolar covalent
Pure water can ionize into
positively charged protons (H+) and negatively charged hydroxide (OH-) ions.
To freeze water, energy is:
released
The concentration of a liquid is defined as the amount of ______ dissolved in a unit volume of solution.
solute
Solutes dissolved in a solvent form a(n)
solution
A liquid that can dissolve substances is known as a(n)
solvent
The amount of heat energy required to raise the temperature of 1 gram of a substance by 1 degree C is defined as
specific heat
When water freezes
the rate of hydrogen bond breakage slows. , water molecules are packed into a more orderly formation.
About 60-70 % of human body weight is composed of __________ which is a vital component of living organisms
water
An aqueous solution is one in which the solvent is:
water
If the pH of a solution is 6, what is the concentration of protons?
10^-6M
Consider a solution with a pH of 8. The concentration of H+H+ ions in the solution would be Blank______.
10^-8 M
What is the normal pH range of living cells
6.5-7.8
Identify the molecules that are predicted to easily dissolve in water.
Ions that carry full electric charges. , Carbohydrates that contain -OH groups.
What is the heat of fusion of a substance?
The amount of heat energy that must be withdrawn or released from a substance to change it from a liquid to a solid
What characteristics describe hydrophobic molecules?
They contain many nonpolar covalent bonds. , They are relatively insoluble in water
What are the concentrations of H+ and OH- ions in pure water?
[OH-] = 10-7 M [H+] = 10-7 M
Compared with liquid water, ice has
a more orderly arrangement of water molecules , more hydrogen bonds between individual water molecules.
The property of water that refers to its ability to be attracted to and adhere to a surface that is not electrically neutral is _______
adhesion
With respect to pH, blood in the human body is within a narrow range of values that are considered to be slightly:
alkaline
The surface tension of water
allows it to form dropplets
A solution in which water is the solvent is called a(n) __________ solution.
aqueous
To dissolve in water, a substance must
be electrically attracted to water
What type(s) of compound(s) minimize pH fluctuations in the fluids of living organisms?
buffer, buffering agent
Living organisms minimize changes in their internal pH using compounds called Blank______.
buffers
Heat _______ refers to the amount of heat energy required to raise the temperature of an entire object, such as a body of water.
capacity
The movement of water through the vessels in a plant is aided by the property of water called
cohesion
The phenomenon of water molecules attracting each other is called
cohesion
Water molecules are attracted to each other in a property called _______ which aids in the movement of water through vessels in plants
cohesion
The amount of solute (in grams) dissolved in a given volume of solution is the solution's
concentration
Because exercise produces lactic acid, it may:
decrease the pH of body fluids.
Compared to a small puddle of water, a lake has
higher heat capacity, but the same specific heat
High specific heat, surface tension, and cohesion are several properties of water involving ____ bonds
hydrogen
Hydrochloric acid is considered an acid because it releases ______ ions into solution.
hydrogen
Sodium hydroxide is a base because when dissolved in water it binds _________ ions that are in solution.
hydrogen
The considerable amount of heat it takes to boil water is due to the collective strength of many _______ bonds.
hydrogen
Water can coat and lubricate surfaces of plants and animals because it can form ______ bonds with the surface through the process of adhesion.
hydrogen
Water easily adheres to the surface of paper towels through the process of adhesion because it forms _____ bonds with the partial negative and positive charges of the paper.
hydrogen
When water is heated, the rate at which __________bonds break increases, and water molecules are converted to the ________ state.
hydrogen , gaseous
The addition of solutes to water will
increase its boiling point. decrease its freezing point.
The addition of solutes to water will:
increase its boiling point. decrease its freezing point.
Which of the following changes in the physical state of water require the input of energy?
liquid to gas , solid to liquid
Hydrophobic molecules tend to contain many _______ covalent bonds, such as the bond between two carbon atoms or the bond between carbon and hydrogen.
nonpolar
Colligative properties depend on the ______ dissolved in a solution.
number of particles
When NaCl dissolves in water, Na+ becomes surrounded by the partially negatively charged _____________ atoms of water molecules, and Cl- becomes surrounded by the partially positively charged __________ atoms of water molecules.
oxygen , hydrogen
Substances dissolved in liquid are known as
solutes
A solution is formed when___________ are dissolved in a(n) ________
solutes , solvent
Substance A has a higher specific heat than substance B. Which requires the most energy to heat equal masses of A and B to the same temperature? Assume all other factors are equal.
substance A
The attraction between molecules at the surface of a liquid is called
surface tension
The attraction between molecules at the surface of a liquid is called:
surface tension
Water has a high heat of vaporization because of
the high number of hydrogen bonds between molecules.
What happens to the pH of a solution when H+ ions are added to it?
the pH decreases
Cohesion of water is defined as:
the property of water molecules attracting each other.
