Exploring Mixtures and their Separation

Comprehensive vocabulary flashcards detailing types of mixtures, concentration formulas, laboratory separation techniques, and colloidal properties from Chapter 5.

Homogeneous Mixture (Solution)

A mixture that has a completely uniform composition throughout, such that any sample has identical properties (e.g., sugar dissolved in water, vinegar, or aerated drinks).

Heterogeneous Mixture

A non-uniform mixture in which the components remain physically separate and distinct, and often settle over time (e.g., sand and water, oil and water).

Solute

The substance in a solution that dissolves into the dissolving medium (e.g., sugar in a sugar-water solution).

Solvent

The substance in a solution that dissolves the solute (e.g., water in a sugar-water solution).

Concentration of a Solution

The amount of solute dissolved in a given amount of solvent or total solution.

Dilip Mahalanabis

An Indian paediatrician who first developed and implemented the treatment for dehydration caused by diseases such as diarrhoea and cholera by formulating the Oral Rehydration Solution (ORS), which was popularised worldwide by the WHO.

Mass by Mass Percentage ($\% \text{ m/m}$)

A method to express concentration representing the grams of solute present per $100\text{ g}$ of total solution: $\text{Mass by mass percentage} = \frac{\text{Mass of solute}}{\text{Mass of solution}} \times 100$.

Mass by Volume Percentage ($\% \text{ m/v}$)

A concentration unit expressing the grams of solute dissolved in $100\text{ mL}$ of total solution: $\text{Mass by volume percentage} = \frac{\text{Mass of solute}}{\text{Volume of solution}} \times 100$.

Volume by Volume Percentage ($\% \text{ v/v}$)

A concentration unit used for mixtures of miscible liquids that expresses the volume of solute in millilitres present per $100\text{ mL}$ of total solution: $\text{Volume by volume percentage} = \frac{\text{Volume of solute}}{\text{Volume of solution}} \times 100$.

Normal Saline Solution

A medical drip solution containing $0.9\%\text{ m/v}$ sodium chloride in water ($0.9\text{ g}$ of salt dissolved per $100\text{ mL}$ of solution), safe for blood transfusion to replace lost bodily fluids.

Solubility

The maximum amount of solute (in grams) that can dissolve in a fixed quantity of solvent ($100\text{ g}$ or $100\text{ mL}$) at a specified temperature.

Saturated Solution

A solution that has dissolved the maximum possible amount of solute at a given temperature, such that no more solute can dissolve at that temperature.

Solubility Curve

A graphical representation showing how the solubility of a given substance in a solvent varies as a function of temperature.

Crystal

A solid composed of atoms, ions, or molecules arranged in an orderly, repeating regular geometric pattern.

Crystallization

A separation and purification technique based on temperature-dependent solubility differences, where a hot, saturated solution is cooled to separate the pure solid substance out as crystals.

Panga Salt

Salt historically produced by coastal communities in India by boiling concentrated sea brines.

Karkatch Salt

Salt historically obtained by coastal Indian communities through the open-air solar evaporation of seawater.

Distillation

A separation technique that separates miscible liquids with a difference in boiling points of at least about $25\,^\circ\text{C}$ (or recovers a liquid from dissolved solids) by boiling the liquid with the lower boiling point into vapour and condensing it back into a pure liquid distillate.

Deg-Bhapka Method

A traditional Indian distillation technique preserved across generations in Kannauj, Uttar Pradesh, used to extract delicate floral fragrances and make natural perfumes such as Mitti ka Ittar.

Fractional Distillation

A distillation process used to separate components of a mixture having relatively small boiling point differences (less than $25\,^\circ\text{C}$), such as refining crude petroleum into petroleum gas, petrol, kerosene, diesel, and bitumen.

Paper Chromatography

A technique used to separate components of a dissolved mixture (such as dyes, inks, or plant pigments) based on differences in their partition and rates of movement between a mobile liquid solvent and the stationary paper surface.

Immiscible Liquids

Liquids that do not dissolve in or blend with one another, forming separate and distinct layers based on differences in density when brought together (e.g., oil and water).

Separating Funnel

A piece of laboratory glassware equipped with a stopcock used to isolate and separate two immiscible liquids having different densities layer by layer.

Sublimation

The phase transition where a solid converts directly into a gas or vapour upon heating (below its melting point) without first passing through the liquid state.

Deposition

The phase transition where a vapour cools and converts directly into a solid without becoming an intermediate liquid.

Alloy

A homogeneous mixture of two or more metals, or a metal with a non-metal, prepared in molten state to produce enhanced properties such as greater strength and corrosion resistance (e.g., brass, bronze, stainless steel).

Suspension

A heterogeneous mixture in which insoluble solid particles (larger than $1000\text{ nm}$ in diameter) do not dissolve but remain suspended throughout the bulk of a liquid medium and settle down upon standing.

Centrifugation

A separation method in which a liquid mixture is spun rapidly in tubes at high speed, generating centrifugal force that forces denser particles outward to collect at the bottom while lighter liquid stays on top.

Paperfuge

A low-cost, human-powered centrifuge constructed from a paper disc and string that spins blood samples at high velocities without electrical power to aid point-of-care medical testing in remote areas.

Coagulation

The process of adding a chemical agent (coagulant, such as powdered alum) to clump fine suspended particles together into larger aggregations that readily settle under gravity.

Colloid

A heterogeneous mixture with particle diameters ranging from $1\text{ to }1000\text{ nm}$, where the particles remain permanently suspended without settling out and are small enough to pass through ordinary filter paper.

Tyndall Effect

The scattering of a visible light beam by colloidal or suspended particles present in a transparent medium, illuminating the pathway of the light beam.

Dispersed Phase

The solute-like component consisting of dispersed microscopic particles suspended within a colloid.

Dispersion Medium

The continuous bulk phase or medium in which the dispersed particles of a colloid are distributed.

Emulsion

A class of colloid in which both the dispersed phase and the dispersion medium are liquids (categorised as oil-in-water or water-in-oil).