Chemical Properties of Gases

Flashcards on chemical reactivity of gases, noble gases, combustible gases, and stoichiometric calculations.

Chemical Reactivity

The capacity of a substance to react under the effect of an energy source or contact with other substances.

Gas Identification

A gas that makes the lime water cloudy, indicating the presence of carbon dioxide.

Noble Gases

Gases that are chemically stable due to their electron configuration, found as simple elements in nature.

Argon

The most abundant noble gas, making up about 1% of the air.

Comburant

A substance that causes combustion and is also known as an oxidant.

Dioxygen (O2)

The most common comburant on Earth, making up about 21% of the atmosphere.

Ozone (O3)

A very reactive form of oxygen used for disinfection and bleaching, also a component of smog.

Fluorine (F)

A highly reactive element that is difficult to preserve and attacks glass and many metals.

Combustible

A flammable substance that burns in the presence of a comburant, releasing energy.

Hydrocarbons

Substances containing only hydrogen and carbon atoms, with low molar mass gases like methane, propane and butane existing at ambient conditions.

Diazote

A stable molecule with a triple bond, making up 78% of the atmosphere and essential for life.

Stoichiometric Calculations

Calculations that determine the quantities of reactants needed and products formed in a reaction.

Kinetic Energy

The energy associated with movement.

Potential Energy

Stored energy.

Heat

A transfer of thermal energy between two mediums of different temperatures.

Endothermic Reaction

A matter transformation that absorbs energy.

Exothermic Reaction

A matter transformation that releases energy.

Thermal Equation

A chemical equation that specifies the amount of energy exchanged in a reaction.

Enthalpy

Symbol H, the amount of energy linked to its internal energy.

Enthalpy Variation

Symbolized by ΔH, represents the energy absorbed or released by a reaction at constant temperature and pressure.

Energy balance

Allows the calculation of the sum of energy absorbed when breaking bonds and the energy released when forming new bonds.

Activation Energy

The amount of energy required to start a reaction.

Calorimeter

An isolated device used to take measurements to perform calorimetry calculations.

Calorimetry

An experimental method for determining the heat of a reaction using the amount of energy absorbed or released in an isolated system at constant pressure.

Molar Heat of Dissolution

The amount of energy absorbed or released when dissolving one mole of solute into a solvent.

Molar Heat of Acid-Base Neutralization

The amount of energy absorbed or released during the neutralization of one mole of acid or base.

Hess's Law

States that when a reaction is the algebraic sum of two or more reactions, then the heat from this reaction is equivalent to the algebraic sum of the heats of reaction which were used to establish this sum.

Reaction Rate

The change in the amount of products or reactants per unit of time.

Elastic Collision

Occurs when particles of reactants meet without leading to the formation of products.

Effective Collision

Occurs when reactants have enough energy to react, there is the formation of products.

Concentration of Reactants

Influences the rate of a reaction. In general, the higher the concentration of reactants, the faster the reaction rate.

Temperature of the System

Influences reaction rate. In general, the more that temperature increases, the more the kinetic energy of the particles increases; this makes the number of particles that have the minimum energy to react bigger, which makes the reaction faster.

Catalyst

A substance that increases the rate of a chemical reaction by lowering its activation energy.

Inhibitor

A substance that decreases the rate of reaction by increasing a reaction’s activation energy.

Complete Reaction

When at least one of the reactants turns completely into products.

Reversible Reactions

Occur when reactions can go both ways at the same time: forwards and backwards take place at the same time.

Chemical Equilibrium

In a closed system, where the matter and energy are not exchanged with the environment, the rate of forward and reverse reactions becomes identical, so all traits are stabilized (concentrations, pressure, color).