Chapter 3

Which of the following solutions has the greatest concentration of hydrogen ions [H+]

gastric juice at pH 2

Desert rabbits are adapted to the warm climate because their large ears aid in the removal of heat due to the

high heat of vaporization of water

What determines the cohesiveness of water molecules

hydrogen bonds

Which bonds must be broken for water to vaporize

hydrogen bonds

Hydrophobic substances such as vegetable oil are

nonpolar substances that repel water molecules

In a single molecule of water, the two hydrogen atoms are bonded to a single oxygen atom by

polar covalent bonds

Which of the following solutions has the greatest concentration of hydroxide ions [OH-]

seawater at pH 8

An example of a hydrogen bond is the bond between

the H of one water molecule and the O of another water molecule

Water is able to form hydrogen bonds because

the bonds that hold together the atoms in a water molecule are polar covalent bonds

One mole (mol) of a substance is

- 6.02 × 1023 molecules of the substance. - the molecular mass of the substance expressed in grams

Buffers are substances that help resist shifts in pH by

- donating H+ to a solution when they have been depleted - accepting H+ when they are in excess

What do cohesion, surface tension, and adhesion have in common with reference to water

All are properties related to hydrogen bonding

Which of the following ionizes completely in solution and is considered to be a strong acid

HCl

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.

At what temperature is water at its densest

4°C

What is true when an ice cube cools a drink

Kinetic energy in the drink decreases

Which of the following ionizes completely in solution and is considered to be a strong base

NaOH

What statements is true about buffer solutions

They maintain a relatively constant pH.

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called

a hydrogen bond

Water's high specific heat is mainly a consequence of the

absorption and release of heat when hydrogen bonds break and form

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

Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon

the release of heat by the formation of hydrogen bonds