Ai I RHEMA CHEMISTRY TEST QUESTIONS

A comprehensive set of vocabulary flashcards derived from chemistry test questions covering periodic trends, stoichiometry, equilibrium, thermodynamics, organic functional groups, and redox reactions.

First Ionization Energy

The energy required to remove an electron from an atom; in the sequence $Na$, $Mg$, $Al$, and $Si$, Silicon ($Si$) possesses the highest value.

Oxidation number of sulfur in $H_2SO_4$

The oxidation state of the sulfur atom in sulfuric acid, which is $+6$.

Benzene and Bromine Water

A compound that will not decolourize bromine water at room temperature, unlike alkenes or alkynes.

Equilibrium Constant ($K_c$)

A value representing the ratio of product concentrations to reactant concentrations at equilibrium; for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$, it is given as $64$ at $500 K$.

Strongest Acid

Among halogen oxoacids like $HClO$, Perchloric acid ($HClO_4$) is the strongest.

Solubility Product ($K_{sp}$)

The equilibrium constant for a solid substance dissolving in an aqueous solution; for $AgCl$, it is $1.8 \times 10^{-10}$.

Coordinate Covalent Bond

A type of bond where both shared electrons come from the same atom, exemplified by the bond in the ammonium ion ($NH_3 \rightarrow H^+$).

Le Chatelier's Principle (Right Shift)

Conditions like decreasing temperature (for exothermic reactions) or increasing pressure that cause an equilibrium to favor the products.

Empirical Formula vs. Molecular Formula

The simplest ratio of atoms (e.g., $CH_2O$) versus the actual number of atoms; for a compound with molar mass $90 g/mol$, the formula for $CH_2O$ becomes $C_3H_6O_3$.

Amphoteric Oxide

An oxide that can react as both an acid and a base, such as Aluminum oxide ($Al_2O_3$).

Redox in Iron and Copper Sulfate

In the reaction $Fe + CuSO_4 \rightarrow FeSO_4 + Cu$, $Fe$ is oxidized and $Cu$ is reduced.

Colligative Properties

Properties depending on the number of particles in solution, including relative lowering of vapour pressure, boiling point elevation, and osmotic pressure.

pH of $0.01 M HCl$

The power of hydrogen for a $0.01 M$ hydrochloric acid solution, which is $2$ (calculated as $-log[0.01]$).

Hybridization of $SF_6$

The mixing of atomic orbitals in Sulfur hexafluoride which results in $sp^3d^2$ hybridization.

Cell Potential ($E_{cell}$)

The electromotive force of a cell; for $Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s)$, it is calculated as $+1.10 V$ using $E = +0.34 V - (-0.76 V)$.

Primary Alcohol

An alcohol where the carbon atom holding the $-OH$ group is attached to only one other carbon, such as Ethanol ($CH_3CH_2OH$).

Rate Law

An equation relating the reaction rate to concentrations ($Rate = k[A][B]$); doubling $[A]$ and halving $[B]$ results in no change to the rate.

Electrophilic Substitution

A reaction where an electrophile replaces a group on a molecule; characteristic of aromatic compounds like Benzene.

Bond Length Order

The ranking of bond distances where triple bonds are shortest and single bonds are longest ($C \text{ triple bond } C < C \text{ double bond } C < C \text{ single bond } C$).

Tollens' Reagent

A chemical reagent used to distinguish between an aldehyde (like propanal) and a ketone (like propanone).

Non-electrolyte

A substance that does not ionize or conduct electricity in water, such as Glucose ($C_6H_{12}O_6$).

Common Ion Effect

The reduction in solubility of an ionic compound when a salt containing a shared ion is added.

Hydrogen Bonding in HF

The intermolecular force that explains why $HF$ has a significantly higher boiling point than $HCl$.

IUPAC Name of $CH_3-CH_2-COOH$

The systematic name for the three-carbon carboxylic acid, which is Propanoic acid.

Electronegativity

The tendency of an atom to attract a bonding pair of electrons; Fluorine ($F$) has the highest electronegativity among all elements.

Buffer Solution

A solution that resists changes in $pH$ when small amounts of an acid or a base are added.