Catalytic Converters and Reaction Rates

Vocabulary flashcards summarizing key terms from the lecture on catalytic converters and factors influencing chemical reaction rates.

Catalytic Converter

Device installed in car exhaust systems that uses catalysts in honeycomb filters to convert harmful pollutants into less harmful gases, reducing air pollution.

Reaction Rate

The speed at which reactants are transformed into products during a chemical reaction.

Temperature (Effect on Reaction Rate)

Measure of average molecular energy; higher temperatures increase molecular motion and collision frequency, accelerating reactions.

Concentration (Chemistry)

Amount of solute per unit volume of solvent (e.g., g/L); higher concentrations mean more molecules in the same space and faster reactions.

Surface Area (Effect on Reaction Rate)

Total exposed area of a solid reactant; increasing it provides more collision sites and speeds up reactions.

Catalyst

Substance that lowers activation energy and speeds up a reaction without being consumed.

Enzyme

Biological catalyst (e.g., digestive enzymes in saliva) that accelerates reactions in living organisms.

Inhibitor

Substance that slows down or stops a chemical reaction, often by interfering with a catalyst.

Carbon Monoxide (CO)

Poisonous, colorless gas from incomplete combustion; converted to less harmful CO₂ in catalytic converters.

Carbon Dioxide (CO₂)

Relatively harmless gas produced from the oxidation of CO and hydrocarbons in catalytic converters.

Hydrocarbons

Unburned fuel molecules composed of hydrogen and carbon; converted to CO₂ and H₂O in catalytic converters.

Nitrogen Oxides (NOₓ)

Polluting gases formed from nitrogen and oxygen at high engine temperatures; reduced to N₂ and O₂ by catalysts.

Collision Theory

Idea that chemical reactions occur when atoms or molecules collide with sufficient energy and proper orientation.

Activation Energy

Minimum energy required for reactants to undergo a chemical reaction; catalysts lower this barrier.

Honeycomb Filter

High-surface-area structure inside catalytic converters that holds catalyst materials and maximizes gas contact.

Nitrogen Oxide Reduction Equation

2 N₂O₃ → 2 N₂ + 3 O₂, a catalytic-converter reaction converting nitrogen oxides to harmless gases.

Pollutant Conversion

Chemical transformation of toxic exhaust gases (CO, hydrocarbons, NOₓ) into less harmful substances (CO₂, H₂O, N₂, O₂) inside a catalytic converter.

Solute

Substance dissolved in a solvent to form a solution; its amount is used in concentration calculations.

Solvent

Liquid or medium in which a solute is dissolved; its volume is used to express concentration.

Mass per Unit Volume (g/L)

Common unit for expressing concentration: grams of solute per liter of solution.