Chemistry Grade IX: Physical States of Matter and Solutions

Vocabulary flashcards covering core definitions, gas laws, and solution chemistry from Chemistry Grade IX Unit 05 (Physical States of Matter) and Unit 06 (Solutions).

Molarity

The number of moles of solute dissolved per $dm^3$ (litre) of solution.

Solubility

The amount of solute in grams dissolved in $100\,\text{grams}$ of the solvent to prepare a saturated solution at a given temperature.

Immiscible

Liquid solutes and solvents that are not soluble in each other.

Completely Miscible

Liquids that dissolve freely in one another in any proportion.

Colloids

A mixture that has particles intermediate in size between solutions and suspensions ($1\,\text{nm} - 1000\,\text{nm}$ in diameter) to form colloidal dispersions.

Tyndall Effect

The phenomenon that occurs when light is scattered by colloidal particles dispersed in a transparent medium.

Suspension

A heterogeneous mixture of undissolved particles in a given medium, where the particles are large enough to be seen with the naked eye.

Sedimentation

The process of settling of undissolved particles at the bottom of a mixture.

Solution

A homogeneous mixture of two or more than two substances.

Aqueous Solution

A solution that is formed by dissolving a substance in water.

Solute

The component of a solution which is present in a smaller amount.

Solvent

The component of a solution which is present in a larger amount.

Saturated Solution

A solution that cannot dissolve any further amount of solute at a particular temperature.

Unsaturated Solution

A solution that can dissolve a further amount of solute at a particular temperature.

Supersaturated Solution

A solution that contains more solute than the amount required to saturate it at a particular temperature.

Concentration

A measure of the amount of solute in a given amount of solvent or solution.

Dilute Solution

A solution which contains a small amount of solute dissolved in the solvent.

Concentrated Solution

A solution which contains a large amount of solute dissolved in the solvent.

Percentage (Solution Concentration)

The number of parts of solute present in $100$ parts of solution.

Amorphous Solid

A solid that lacks an ordered arrangement of its particles (such as rubber, glass, or plastic).

Crystalline Solids

Solids in which particles (ions, atoms, or molecules) are arranged in regular three-dimensional patterns.

Allotropy

The phenomenon in which an element exists in more than one physical state and phase (known as allotropes or allotropic forms).

Transition Temperature

The temperature at which one allotrope changes into another allotropic form.

Gas

The highest energy state of matter.

Diffusion

The spontaneous mixing of molecules of different gases or particles to form a homogeneous mixture by random motion and molecular collisions, moving from higher to lower concentration.

Effusion

The escape of molecules in the gaseous state one by one without collision through a hole of molecular dimension.

Pressure ($P$)

The force ($F$) exerted by a gas per unit area ($A$) of a container.

Compressibility

The change in volume per unit change in pressure of a substance.

Density

The mass per unit volume of a substance.

Boyle's Law

A gas law stating that the volume ($V$) of a given mass of gas decreases with an increase in pressure ($P$) at constant temperature.

Charles's Law

A gas law stating that the volume of a given mass of gas is directly proportional to the absolute temperature at constant pressure.

Absolute Temperature

Temperature measured on the Kelvin scale.

Evaporation

The spontaneous change of a liquid into the gaseous state.

Vapour Pressure

The pressure exerted by the vapours of a liquid when the rate of evaporation becomes equal to the rate of condensation.

Boiling Point

The temperature at which the vapour pressure of a liquid becomes equal to the atmospheric pressure (such as $101.325\,\text{kilo Pascal}$) or any external pressure.

Freezing Point

The temperature at which the liquid and solid states of a substance coexist in dynamic equilibrium.

Melting Point

The temperature at which a solid starts melting and exists in dynamic equilibrium with the liquid state.