Determination of the Composition of the Initial System: Mass, Volume, and Amount of Substance

Flashcards covering key vocabulary, formulas, and fundamental definitions regarding amount of substance, molar mass, molar volume, concentrations, and solubility.

Mole

The unit of amount of substance defined as a pack of $N_A = 6.02 \times 10^{23}$ microscopic entities (atoms, molecules, or ions).

Avogadro's Constant ($N_A$)

The constant representing the number of entities per mole, defined as exactly $6.02214076 \times 10^{23}\text{ mol}^{-1}$.

Number of Entities ($N_x$)

The total dimensionless count of microscopic particles in a sample, given by $N_x = n_x \times N_A$, where $n_x$ is the amount of substance in moles.

Molar Mass ($M_x$)

The ratio of the mass $m_x$ of a pure chemical sample to its amount of substance $n_x$, expressed by $M_x = \frac{m_x}{n_x}$ with units of $\text{g}\text{ mol}^{-1}$.

Molar Volume ($V_{m,x}$)

The ratio of the volume $V_x$ of a pure sample of a chemical species to its amount of substance $n_x$, defined by $V_{m,x} = \frac{V_x}{n_x}$ in $\text{L}\text{ mol}^{-1}$.

Gas Molar Volume at Standard Conditions

The molar volume common to all gases at $1013\text{ hPa}$, which equals $22.4\text{ L}\text{ mol}^{-1}$ at $0^\text{o}\text{C}$ and $24\text{ L}\text{ mol}^{-1}$ at $20^\text{o}\text{C}$.

Mass Density ($\rho_X$)

The ratio of the mass $m_X$ of a sample of substance $X$ to its volume $V_X$, expressed by the formula $\rho_X = \frac{m_X}{V_X}$.

Solution

A homogeneous mixture formed when one or more chemical species (solutes) dissolve into a liquid (solvent).

Solute

The minority chemical species (solid, liquid, or gas) dissolved in a solvent within a solution.

Solvent

The majority liquid component of a solution that dissolves solute species.

Aqueous Solution

A specific solution in which water serves as the solvent, denoted by the suffix $(aq)$ on dissolved species formulas.

Mass Concentration ($t_{\text{soluté}}$ or $C_m$)

The ratio of dissolved solute mass $m_{\text{soluté}}$ to total solution volume $V_{\text{solution}}$, given by $t_{\text{soluté}} = \frac{m_{\text{soluté}}}{V_{\text{solution}}}$ in $\text{g}\text{ L}^{-1}$.

Molar Concentration ($c_{\text{soluté}}$ or $C$)

The ratio of the amount of substance of dissolved solute $n_{\text{soluté}}$ to total solution volume $V_{\text{solution}}$, given by $c_{\text{soluté}} = \frac{n_{\text{soluté}}}{V_{\text{solution}}}$ in $\text{mol}\text{ L}^{-1}$.

Effective Molar Concentration ($[A_{(aq)}]$)

The molar concentration of a specific dissolved entity $A_{(aq)}$ in solution, calculated as $[A_{(aq)}] = \frac{n_{A_{(aq)}}}{V_{\text{solution}}}$.

Solubility

The maximum concentration of solute that can be dissolved in a given solvent at a specified temperature.

Saturated Solution

A solution whose dissolved solute concentration has reached its solubility limit for a given temperature.

Recrystallization

A purification method where a saturated solution is cooled to reduce solubility, causing pure solute crystals to precipitate out.

Solvent Extraction

A technique used to extract a solute from one solvent into another immiscible solvent in which the solute has higher solubility.