Mole Concept and Stoichiometry Practice Flashcards

Complete set of vocabulary flashcards covering the Mole Concept, gas laws, density types, concentration terms, and stoichiometric principles described in the lecture.

Dalton's Atomic Theory

A theory stating that matter is composed of small indivisible particles called atoms that can neither be created nor destroyed.

Relative Atomic Mass (R.A.M.)

The ratio calculated as $\frac{\text{Mass of 1 atom of element}}{\frac{1}{12} \times \text{mass of one C-12 atom}}$, which is equivalent to the total number of nucleons in the atom.

Atomic Mass Unit (A.M.U.)

A unit of mass defined as $\frac{1}{12} \times \text{mass of one C-12 atom}$, approximately equal to $1.66 \times 10^{-24}\,g$ or $1.66 \times 10^{-27}\,kg$.

Unified Mass (U) or Dalton (Da)

Alternative names for the Atomic Mass Unit (A.M.U.).

Atomic Mass

The mass of a single atom of an element, calculated using the formula $\text{R.A.M.} \times \text{amu}$.

Gram Atomic Mass (G.A.M.)

The mass of one mole of atoms ($6.022 \times 10^{23}$ atoms) of an element expressed in grams.

Molar Volume at STP/NTP

The volume occupied by one mole of any ideal gas at Standard Temperature and Pressure, which is $22.4\,L$.

Absolute Density (for Solids and Liquids)

The mass per unit volume of a substance, typically expressed as $d = \frac{m}{V}$ with units like $g/mL$.

Relative Density (R.D.)

The unitless ratio of the density of a substance to the density of water at $4^\circ C$ ($1\,g/mL$); also known as specific gravity.

Absolute Density (for Gases)

Density calculated for gases using the formula $d = \frac{PM}{RT}$, where $P$ is pressure, $M$ is molecular weight, $R$ is the gas constant, and $T$ is temperature in Kelvin.

Vapour Density (V.D.)

A unitless value representing the density of a gas with respect to Hydrogen gas, defined as $\text{V.D.} = \frac{M}{2}$ where $M$ is the molecular weight.

Limiting Reagent (L.R.)

The reactant in a chemical reaction that is completely consumed first, limiting the amount of product that can be formed.

Percentage Purity

The ratio of the mass of a pure compound to the total mass of the sample, expressed as $\frac{\text{Mass of pure compound}}{\text{Mass of sample}} \times 100$.

Principle of Atom Conservation (P.O.A.C.)

A principle based on the law of conservation of mass which states that the number of moles of atoms of an element remains constant throughout a chemical reaction.

Empirical Formula (E.F.)

The simplest whole-number ratio of atoms of each element present in a compound.

Molecular Formula (M.F.)

The actual number of atoms of each element in a molecule, determined by the formula $\text{M.F. = (E.F.)} \times n$.

% w/w (Percentage by Weight)

A temperature-independent concentration term defined as $\frac{\text{Mass of solute}}{\text{Mass of solution}} \times 100$.

% w/v (Percentage Weight by Volume)

A temperature-dependent concentration term defined as $\frac{\text{Mass of solute}}{\text{Volume of solution (mL)}} \times 100$.

% v/v (Percentage Volume by Volume)

A temperature-dependent concentration term defined as $\frac{\text{Volume of solute}}{\text{Volume of solution}} \times 100$.

Mole Fraction (X)

A temperature-independent ratio of the moles of one component to the total moles in a mixture, such that $X_A + X_B = 1$.

Molality (m)

A temperature-independent concentration measure defined as the number of moles of solute present in $1\,kg$ of solvent.

Molarity (M)

A temperature-dependent measure of concentration defined as the number of moles of solute present in $1\,L$ of solution.

Law of Reciprocal Proportion

A law of chemical combination illustrated by atoms combining in specific ratios, such as Carbon combining with Oxygen to form $CO_2$ and with Sulphur to form $CS_2$.