College ChemistryFree College-Level Chemistry practice test

Correct answer: E. Gold(I) chloride

In the classical nomenclature system, metals with multiple oxidation states use the suffixes -ous (lower state) and -ic (higher state). Gold in the +1 state is "aurous," while gold in the +3 state is "auric." The modern IUPAC system replaces these Latin suffixes with Roman numerals in parentheses.

Correct answer: D. An alcohol has a terminal -OH group; an ether has an oxygen bonded to two carbon atoms

The defining feature of an alcohol is a hydroxyl group (-OH) attached to the end or branch of a carbon chain. An ether, by contrast, has an oxygen atom bridging two separate carbon atoms (R-O-R). These structural differences give the two classes very different reactivities. Note that an ester — not an ether — contains an oxygen adjacent to a carbonyl (C=O) group.

Correct answer: D. Largest atomic radius

Ionization energy decreases as atomic radius increases because the outermost electrons are situated farther from the nucleus. The electrostatic attraction between the positively charged nucleus and the valence electrons weakens with distance, so atoms with the largest radius hold their electrons most loosely. Among the noble gases, the heavier ones (like Xe and Rn) are the easiest to ionize for this reason.

Correct answer: D. CN⁻ (cyanide ion)

Although the cyanide ion (CN⁻) contains a carbon atom covalently bonded to nitrogen, it is classified as inorganic. Organic molecules characteristically contain carbon bonded to hydrogen; other atoms like nitrogen, oxygen, or halogens appear as minority substituents. The structurally similar nitrile functional group (C≡N attached via a C-C bond to a larger carbon framework) is organic, but the isolated CN⁻ ion is not.

Correct answer: B. Ether

An ether consists of an oxygen atom flanked by two carbon atoms via single bonds (R-O-R'), with no double bond to carbon. All the other functional groups listed — esters, aldehydes, ketones, and carboxylic acids — contain a carbonyl group (C=O) as part of their defining structure.

Correct answer: B. Radius decreases because additional protons exert greater nuclear attractive force

Traversing a period adds both protons and electrons simultaneously, but the effect of each added proton outweighs the effect of the corresponding electron in the same subshell. The increased nuclear charge pulls the electron cloud inward more tightly, shrinking the atomic radius progressively across a period.

Correct answer: B. Polarizability decreases

Going down a group, atomic radius increases, and larger atoms have valence electrons that are farther from the nucleus and more loosely held. Loosely held electrons are more easily displaced, meaning polarizability actually increases — not decreases — down the group. This greater polarizability also strengthens London dispersion forces and raises melting/boiling points. Electronegativity decreases and metallic character increases, as expected.

Correct answer: E. Aluminum hydroxide

For ionic compounds containing a metal and a polyatomic anion, the metal retains its name and the anion is named as a unit. The hydroxide ion (OH⁻) is a recognized polyatomic ion, so the compound is named as a unit — not broken into individual atoms as "oxyhydride" would imply. The number of hydroxide groups is omitted because charge balance (Al³⁺ with three OH⁻) is implied.

Correct answer: B. Lithium fluoride

For a binary compound composed of a metal and a nonmetal, the metal keeps its elemental name while the nonmetal receives the -ide suffix. Fluorine (the nonmetal) therefore becomes fluoride, giving the name lithium fluoride.

Correct answer: E. Sulfur trioxide

When naming binary compounds formed by two nonmetals, the first element retains its name (the mono- prefix is dropped when only one atom is present), and the second element takes the -ide suffix along with a Greek prefix indicating count. Three oxygen atoms yield the prefix tri-, making the name sulfur trioxide.