Exam 2: Life, Chemistry, and Water

In the representation of hydrogen gas, H-H, the dash represents two electrons being shared equally.

The attraction between Na⁺cations and Cl^-anions form ____ that hold the ions together in the compound NaCl.

When water molecules exposed to the air form hydrogen bonds between adjacent water molecules below and beside them, molecules in the upper layer become more resistant to separating from those underneath. This property of water is known as ____.

Consider the equilibrium established in the carbonic acid-bicarbonate buffer system, which maintains pH balance in mammalian blood: $\mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{HCO} 3-+\mathrm{H}+$ During hypoventilation, breathing rate decreases, and therefore elimination of CO₂ during exhalation decreases. How is optimal blood pH maintained when acid levels increase in our blood from hypoventilating?

Water has an unusually high boiling point for its molecular weight because water molecules ____.

When added to water, a base will act as a(n) ____ and cause the pH of the solution to ____.

In the presence of water, nonpolar associations form between molecules or regions of molecules that are ____.

A molecule of water in the middle of a chunk of ice will usually have ____ hydrogen bonds with other water molecules.

The substance O₂is considered to be ____.

A polar covalent bond would be most likely to form between ____.

The pH of your stomach is between 1 and 3. Use your knowledge of polar and nonpolar substances to explain why the acids in your stomach do not alter the pH of your blood.

Figure 2.5 The water lattice illustrated in the figure above forms as a result of ____ between water molecules.

Prolonged iodine deficiency causes ____, a condition in which the thyroid gland enlarges so much that the front of the neck swells significantly.

Metallic ions such as Ca²⁺, Na⁺, and Fe³⁺readily form ____.

The chemical bonds that are formed when atoms share electrons equally are called ____.

A mixture of vegetable oil and water will separate into layers because oil is ____ and forms ____.

An oxygen atom has ____ surrounding a nucleus composed of ____.

Proteins in thermophiles must be stabilized by van der Waals forces, because hydrogen bonds cannot be maintained at high temperatures.

In contrast to ionic bonds, covalent bonds ____.

Sodium has one valence electron in its third energy level. To reach a stable energy configuration, sodium will tend to____.