Alkanes 2/3

This set of flashcards covers key concepts related to the combustion of alkanes, environmental chemistry, and free radical reactions.

What is produced during the complete combustion of alkanes?

Carbon dioxide (CO₂) and water (H₂O).

Why are alkanes good fuels

Because people they burn readily to produce large amounts of energy

What is the combustion of alkanes used for

To power vehicles and make electricity

What is a consequence of incomplete combustion of alkanes?

Produces carbon monoxide (CO) and soot.

What to do when writing complete combustion equations

Balance carbons, hydrogens, and then oxygen

Why is carbon monoxide considered poisonous?

It binds to hemoglobin in the blood and prevents oxygen bonding.

What does soot cause

Breathing problems and clogs up engines

What can remove carbon monoxide from combustion gases?

Catalytic converters.

Where does ozone occur

In the lowest levels of the atmosphere

What creates photochemical smog

When solid carbon particulates and ozone mix

What does photochemical smog do

Harms the respiratory system in animals and damages plants and is toxic to humans

What is the greenhouse effect?

The process by which carbon dioxide absorbs infrared radiation from the sun and emits some of it back to Earth, contributing to global warming.

When are oxides of nitrogen made

When nitrogen and oxygen found in the air, combines under high pressure and temperature such as in car engines

What does acid rain do

Damages plants, kills fish and erodes building

What’s type of gas is sulfur dioxide

Acidic

How is sulfur dioxide formed

When fossil fuels containing sulfur based impurities are burnt and then the sulfur reacts with the oxygen, producing sulfur dioxide

What does wet scrubbing involve

Dissolving calcium carbonate or oxide in water and spraying in acidic sulfur dioxide gas

What is the process in initiation called

Photochemical reactions where the bond breaks, producing two radicals

What will propagation do

It will keep going until termination

What causes photochemical smog?

The reaction between ozone, hydrocarbons, and nitrogen dioxide in sunlight.

How do catalytic converters help with air pollution?

They reduce the amount of unburnt hydrocarbons and nitrogen oxides in the atmosphere.

What is acid rain and how is it formed?

Acid rain is caused by sulfur dioxide (SO₂) and nitrogen oxides reacting with water in the atmosphere to form sulfuric and nitric acids.

What process can be used to remove SO₂ from flue gases?

Wet scrubbing using an alkali to neutralize sulfur dioxide.

What are the three main stages of free radical chain reactions?

Initiation, Propagation, and Termination.

What occurs during the initiation stage of a free radical chain reaction?

Radicals are produced, usually using visible or ultraviolet light.

What happens during the propagation stage of a free radical chain reaction?

A radical reacts with a non-radical molecule, creating new radicals that continue the chain reaction.

What marks the termination stage of a free radical chain reaction?

When two radicals react to form a non-radical molecule, ending the reaction.