Ch.3 Mastering Biology

Each water molecule is joined to _____ other water molecules by ____ bonds.

A) three … ionic
B) two … polar covalent
C) four … polar covalent
D) four … hydrogen
E) two … hydrogen

D

The unequal sharing of electrons within a water molecule makes the water molecule _____.

A) have a low surface tension
B) polar
C) hydrophobic
D) ionic
E) change easily from a liquid to gaseous form

B

The tendency of an atom to pull electrons toward itself is referred to as its _____.

A) polarity
B) tonicity
C) ionic potential
D) electronegativity
E) covalency

D

In a water molecule, what type of bond is found between the oxygen and hydrogens?

A) hydrophilic
B) ionic
C) hydrophobic
D) polar covalent
E) nonpolar covalent

D

Which of these is weakest?

A) Covalent bonds
B) Ionic bonds
C) Hydrogen Bonds

C

What stops some insects from drowning on top of water?

A) The insect is swimming.
B) Surface tension.
C) The insect is very light.
D) It is difficult to change the temperature of water.
E) The insect is flying just above the water surface.

B

What is it called when the Hydrogen atom of one water molecule bonds to an Oxygen atom of another water molecule?

Hydrogen Bond

What is it called when two hydrogen atoms bond to an oxygen atom to form a water molecule?

Covalent bonds

In a water molecule, which atoms are slightly positive and which are slightly negative?

Oxygen is slightly negative, Hydrogen is slightly positive

What are these examples of? Water molecules cling to the side of a beaker, and water molecules cling to plant cell walls

Adhesion

What are these examples of? Water molecules are attracted to each other, and a drop of water spilled on a table forms a drop on the table, rather than spreading out over the surface

Cohesion

What are these examples of? A sewing needle floats when it is placed gently on top of water in a bucket, and a water strider runs across a pond without breaking the surface

Surface tension

The table shown here lists the specific heat of several substances in J/g/C

water – 4.18
ethyl alcohol – 2.44
benzene – 1.80
sulfuric acid – 1.40

Based on the information in the table, which of the following statements are true?
Select all that apply.

A) Benzene is more resistant to temperature change than sulfuric acid.
B) Water is less resistant to temperature change than ethyl alcohol.
C) Sulfuric acid is less resistant to temperature change than water.
D) Ethyl alcohol likely exhibits more hydrogen bonding than water.
E) More heat is required to raise the temperature of 1 g of benzene 1 ∘C than to raise the temperature of 1 g of water 1 ∘C.
F) More heat is required to raise the temperature of 1 g of water 1 ∘C than to raise the temperature of 1 g of ethyl alcohol 1 ∘C.
G) Water has a high specific heat due to the hydrogen bonding between water molecules.

A, C, F, G

What process is shown when water gets from the roots of a tree to it’s leaves

A) evaporation
B) push
C) gravity
D) antigravity
E) precipitation

A

Many of water’s emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____.

A) are in constant motion
B) are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively
C) tend to repel each other
D) are extremely large
E) are very small

B

The amount of energy that must be absorbed or lost to raise or lower the temperature of 1 g of liquid water by 1°C _____.

A) is 1,000 calories
B) is 1 kilocalorie
C) is 1,000 kilocalories
D) is 1 calorie
E) depends on the initial temperature of the water sample
F) is 1,000 joules

D

Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water’s _____.

A) ability to form colloids
B) cohesion
C) high specific heat
D) buffering activity
E) lower density in the solid phase

C

If the molecular mass of a carbon atom is 12, the mass of a hydrogen atom is 1, and the mass of an oxygen atom is 16 daltons, how many molecules does one mole of table sugar (sucrose; C12H22O11) contain?

A) (6.02 x 1023)(342)
B) 6.02 x 1023/342
C) 6.02 x 1023
D) 342
E) 45

C

When a water molecule dissociates, what is the positive cation that is created?

A) hydrogen ion
B) water molecule
C) electron
D) hydronium ion
E) hydroxide ion

A

When a water molecule dissociates, what is the negative anion that is created?

A) water
B) hydronium ion
C) hydroxide ion
D) hydrogen ion
E) proton

C

In a neutral solution the concentration of _____.

A) water molecules is less than the concentration of hydroxide ions
B) hydrogen ions is less than the concentration of hydroxide ions
C) water molecules is less than the concentration of hydrogen ions
D) hydrogen ions is greater than the concentration of hydroxide ions
E) hydrogen ions is equal to the concentration of hydroxide ions

E

If the solution on the right has more OH- ions and less H+ ions than the one on the left, this means that the solution is….

A) Both of these solutions are equally acidic.
B) The solution on the right is neutral relative to the solution on the left.
C) Both of these solutions are equally basic.
D) The solution on the right is acidic relative to the solution on the left.
E) The solution on the right is basic relative to the solution on the left.

E

What name is given to a molecule with 3 H atoms and 1 O atom with a +1 charge?

A) glucose
B) hydronium ion
C) methane
D) water
E) hydroxide ion

B

How does a hydronium ion molecule form?

A) Evaporation.
B) Two water molecules bonded.
C) A water molecule gained an hydrogen ion from another water molecule.
D) A hydrogen molecule bonded with an OH- molecule.
E) A water molecule split in half.

C

What name is given to a molecule of one O atom and one H atom with a -1 charge?

A) water
B) hydroxide ion
C) glucose
D) hydronium ion
E) DNA

B

The process of a water molecule becoming an OH- ion and an H+ ion is called ____

A) surface tension
B) dissociation
C) cohesion
D) adhesion
E) specific heat

B

Which of these is the correct equation for the dissociation of water?

A) H2O <==> H+ + OH-
B) H2O + OH-<==> H2O+
C) H2O + H2O+<==> H2O + OH-
D) H2O + H2O <==> H3O+ + OH-
E) H+<==> H2O + H2O+

D

What is the charge on a hydronium ion?

A) 1+
B) 2-
C) 2+
D) 0
E) 1-

A

What is the charge on a hydroxide ion?

A) 2-
B) 1-
C) 0
D) 2+
E) 1+

B

About _____ molecules in a glass of water are dissociated.

A) 1 in 1,000,000,000
B) 1 in 500,000,000
C) 1 in 5,000,000
D) 1 in 1,000,000
E) 1 in 2

B (one in half a billion)

A pH of 6 is how many times more acidic than a pH of 9?

A) 3
B) 30
C) 100
D) 300
E) 1,000

E

Select the statement that best describes a buffer.

A) Buffered solutions are always neutral, with a pH of 7.
B) A buffer prevents the pH of a solution from changing when an acid or base is added.
C) A buffer stabilizes the pH of a solution by preventing acids or bases from dissociating.
D) A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added.
E) A buffer causes acidic solutions to become alkaline, and alkaline solutions to become acidic.

D

Which property of water allows a paper towel to pick up a puddle of water?

A) adhesion of water molecules to other kinds of molecules
B) water’s high surface tension
C) water’s high heat of vaporization

A

Which property of water allows a water strider to walk on water?

A) the formation of covalent bonds between water molecules
B) water’s high surface tension
C) adhesion of water molecules to other kinds of molecules

B

between H+ concentration in an acidic solution such as lemon juice (pH 2) and a basic solution such as household bleach (pH 13)?

A) The H+ concentration of lemon juice is higher than the H+ concentration of household bleach by a factor of 1011 (100 billion).
B) The H+ concentration of lemon juice is higher than the H+ concentration of household bleach by a factor of 11.
C) The H+ concentration of household bleach is higher than the H+ concentration of lemon juice by a factor of 1011 (100 billion).

A