Chapter 2 Test Review: Chemistry Review, Polarity, Properties of Water, Acids and Bases

Vocabulary flashcards covering atomic bonding, polarity, unique properties of water, acids, bases, and buffers from Chapter 2 Test Review.

pH

A scale used to specify the acidity or basicity of an aqueous solution, measuring the relative concentration of hydrogen ions ($H^+$).

Acids and Bases

Acids are substances that increase the concentration of hydrogen ions ($H^+$) in solution, whereas bases decrease the $H^+$ concentration by accepting hydrogen ions or donating hydroxide ions ($OH^-$).

Trace elements

Chemical elements required by an organism in only minute quantities to survive and maintain proper physiological function.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of shared electrons toward itself in a covalent bond.

Chemical bonds

Attractions that hold atoms or ions together to form compounds, typically driven by atoms seeking to fill their valence electron shells.

Covalent bonds

A type of strong chemical bond formed when two atoms share one or more pairs of valence electrons.

Nonpolar covalent bonds

A covalent bond in which the electrons are shared equally between two atoms because they have identical or very similar electronegativities.

Polar covalent bonds

A covalent bond between atoms that differ in electronegativity, causing unequal sharing of electrons and creating partial positive and partial negative charges.

Ionic bonds

A chemical bond resulting from the electrostatic attraction between oppositely charged ions formed by the complete transfer of one or more valence electrons.

Hydrophobic

Substances that lack an affinity for water, usually nonpolar molecules that do not dissolve in or interact favorably with water.

Hydrophilic

Substances that have an affinity for water, typically polar or ionic molecules that readily interact with or dissolve in water.

Adhesion

The attraction between different types of molecules, such as water molecules clinging to plant cell walls or glass surfaces.

Cohesion

The attraction between molecules of the same kind, such as water molecules bonding to one another via hydrogen bonds.

Capillary action

The process of a liquid flowing in narrow spaces without the assistance of, or in opposition to, external forces like gravity, driven by cohesion and adhesion.

Heat capacity

The amount of heat energy required to raise the temperature of a given amount of a substance by a specific temperature interval.

Heat of vaporization

The quantity of heat energy a liquid must absorb for a given amount of it to be converted from a liquid into a gas.

Surface tension

A measure of how difficult it is to stretch or break the surface of a liquid, produced by cohesive forces between liquid molecules at the interface.

Solvent

The dissolving agent in a solution, present in the greatest amount, which dissolves another substance.

Solute

A substance that is dissolved in a solvent to form a homogeneous solution.

Hydrogen bonds

Weak electrostatic attractions that occur when a partially positive hydrogen atom covalently bonded to an electronegative atom is attracted to another electronegative atom.

Buffers

Substances that minimize changes in the concentrations of $H^+$ and $OH^-$ in a solution, thereby stabilizing pH in living systems.