Gas Volumes, Enthalpy, and Catalysts

These flashcards cover essential vocabulary terms related to gas volumes, enthalpy changes, and catalysts as discussed in the lecture.

Mole

A unit of measurement for amount of substance, defined as containing exactly 6.022 x 10²³ particles.

Molar gas volume

The volume occupied by one mole of a gas, typically 24 dm³ at 298 K and 101.3 kPa.

Enthalpy change (ΔH)

The heat change in a reaction at constant pressure, measured in kilojoules per mole.

Exothermic reaction

A chemical reaction that releases heat energy to the surroundings, resulting in a negative ΔH.

Endothermic reaction

A chemical reaction that absorbs heat energy from the surroundings, resulting in a positive ΔH.

Activation energy

The minimum energy required for a chemical reaction to occur.

Catalyst

A substance that increases the rate of a reaction by providing an alternative pathway with lower activation energy.

Calorimetry

The measurement of heat transfer during chemical reactions or physical changes.

Ideal gas equation

An equation of state for an ideal gas, given as PV=nRT, where P is pressure, V is volume, n is amount of substance, R is the gas constant, and T is temperature.

Hess's Law

The principle stating that the total enthalpy change of a reaction is independent of the pathway taken.

Bond enthalpy

The amount of energy required to break one mole of bonds in a gaseous molecule.

Adsorption

The process by which atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to the surface of a solid.

Desorption

The process of releasing adsorbed substance from the surface of a solid.

Bond breaking

The process in which energy is absorbed to break chemical bonds.

Bond forming

The process in which energy is released when chemical bonds are formed.

Gas syringe

A device used to accurately measure the volume of gas produced in a reaction.

Neutralization

The reaction between an acid and a base to produce water and a salt.

Catalytic converter

A device used in vehicles to reduce harmful emissions by converting them into less harmful substances.

Bond length

The average distance between the nuclei of two bonded atoms.

Average bond enthalpy

The mean energy required to break one mole of a bond in a compound across different molecules.