Chapter 3: Water and Life

Fill-in-the-blank practice flashcards covering key concepts from Chapter 3: Water and Life.

Water is the only common substance to exist in Earth's natural environments in all __________ physical states of matter.

three

In a water molecule, electrons of polar covalent bonds spend more time near oxygen than hydrogen because oxygen is more __________ than hydrogen.

electronegative

The four emergent properties of water that facilitate an environment for life are cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a __________.

solvent

Hydrogen bonds holding water molecules together is known as cohesion, whereas __________ is an attraction between different substances, such as between water and plant cell walls.

adhesion

__________ is a measure of how difficult it is to break the surface of a liquid.

Surface tension

The kinetic energy associated with the random motion of atoms or molecules is called __________ energy.

thermal

One calorie ($\text{cal}$) is the amount of heat required to raise the temperature of $1\,g$ of water by __________.

$$1^\circ\text{C}$$

Water resists changing its temperature because of its high __________.

specific heat

Heat is __________ when hydrogen bonds break, and heat is released when hydrogen bonds form.

absorbed

Ice floats on liquid water because hydrogen bonds in ice are more ordered, causing water to reach its greatest density at __________.

$$4^\circ\text{C}$$

When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called a __________.

hydration shell

Oil molecules are hydrophobic because they have relatively __________ bonds.

nonpolar

Molarity ($M$) is defined as the number of moles of solute per __________ of solution.

liter

When a hydrogen atom in a hydrogen bond between two water molecules shifts, leaving its electron behind, it transfers a hydrogen ion ($H^+$), which is a single __________.

proton

A substance that increases the $H^+$ concentration of a solution is an acid, whereas a substance that decreases the $H^+$ concentration is a __________.

base

The pH of a solution is defined mathematically as the negative logarithm of the $H^+$ concentration, represented by the formula __________.

$$pH = -\log[H^+]$$

Substances that resist changes in the concentrations of $H^+$ and $OH^-$ in a solution are called __________.

buffers

About $25\%$ of human-generated $CO_2$ is absorbed by the oceans, where it reacts with seawater to form __________, leading to ocean acidification.

carbonic acid