Chemistry Review: Solubility, Redox, Galvanic Cells, and Stoichiometry

Vocabulary flashcards reviewing core topics including solubility, precipitation, redox reactions, galvanic cells, metal reactivity, and mole concepts.

Ionisation

The process in which a molecular substance reacts with a solvent to form ions in solution, such as polar molecules containing hydrogen reacting with water to form hydronium ions ($H_3O^+$).

Hydronium Ion

The ion ($H_3O^+$) formed when polar molecules containing hydrogen dissolve in water and undergo ionisation.

Ion-Dipole Attraction

The intermolecular force formed between ions (such as $Na^+$ or $Cl^-$) and surrounding polar water molecules during dissolution and hydration.

Dissociation

The separation of individual ions from an ionic lattice when an ionic crystal dissolves in water, after which the ions become surrounded by water molecules.

SNAPE

A mnemonic for remembering ionic salts that are soluble in water: Sodium ($Na^+$), Nitrate ($NO_3^-$), Ammonium ($NH_4^+$), Potassium ($K^+$), and Ethanoate ($CH_3COO^-$).

Insoluble Ionic Compound

An ionic compound that does not dissolve in water because the energy required to separate the ions from the crystal lattice is greater than the energy released when the ions are hydrated.

Precipitation Reaction

A chemical reaction in aqueous solution where dissolved ionic reactants combine to form an insoluble solid product known as a precipitate.

Spectator Ions

Ions present in a reaction mixture that do not undergo chemical change or participate directly in the reaction to form a precipitate.

Oxidising Agent (Oxidant)

A chemical reactant in a redox process that accepts electrons from another reactant and is thereby reduced.

Reducing Agent (Reductant)

A chemical reactant in a redox process that donates electrons to another reactant and is thereby oxidised.

Pyrophosphate Ion

The polyatomic anion $P_2O_7^{4-}$, in which phosphorus exhibits an oxidation state of $+5$.

Cathode (Galvanic Cell)

The electrode in an electrochemical or galvanic cell where reduction occurs, consisting of the less reactive metal / weaker reducing species.

Pop-Test

An identifying test for hydrogen gas ($H_2(g)$), in which the collected gas is ignited and combusts with a characteristic pop sound.

Displacement Reaction

A redox reaction in which a more reactive metal donates electrons to displace a less reactive metal ion from solution, such as $Fe(s)$ displacing $Pb^{2+}(aq)$ and $Ni^{2+}(aq)$.

Avogadro's Constant ($N_A$)

The number of constituent particles per mole of a substance, equal to $6.02 \times 10^{23}\text{ mol}^{-1}$.

Molar Mass ($M$)

The mass of one mole of a given substance, expressed in units of $g\text{ mol}^{-1}$.

Percentage Composition

The proportion by mass of an element or radical in a compound, calculated as $\frac{M(\text{part})}{M(\text{compound})} \times 100$.

Hydrated Salt

An ionic crystal compound containing a fixed stoichiometric ratio of chemically bound water molecules, such as hydrated sodium carbonate ($Na_2CO_3 \times 10H_2O$).