Chemistry - Atmospheric Elements

Question 1

What is the structure of carbon?

Answer 1

It has four valence electrons thus forming one to four bonds with other atoms

Question 2

Alkanes

Answer 2

Compounds of entirely carbon/hydrogen atoms bonded by single bonds.

Question 3

What is the chemical formula for an Alkane?

Answer 3

CnH2n+2

Question 4

What are the first four alkanes?

Answer 4

Methane, Ethane, Propane and n-butane

Question 5

How are alkanes named with side groups?

Answer 5

First by the longest continous chain of carbon as the base, with respective chains numbered.

Question 6

What is an example of alkane nomenclature?

Answer 6

2,4-Dimethylhexane or 2-Bromo-3-Chloropentane

Question 7

How do alkyl radicals form?

Answer 7

From alkanes when a H atom is replaced, remaining with an unpaired electron.

Question 8

What is an example of an alkyl radical?

Answer 8

Methyl, Ethyl, Propyl

Question 9

Why are alkyls important in the atmosphere?

Answer 9

The unpaired electrons make them very reactive.

Question 10

Alkenes

Answer 10

Carbon containing compounds that have a double bond between carbons

Question 11

Examples of alkenes?

Answer 11

Ethene, propene, 1-butene

Question 12

What does the 1 in 1-butene refer to?

Answer 12

The carbon the double bond extends from, from the point closest to the end of the molecule with the double bond

Question 13

Alkadienes

Answer 13

Compounds containing two-double bond like 1,3 Butadiene

Question 14

Alkynes

Answer 14

Hydrocarbons with a single TRIPLE bond

Question 15

Aromatics

Answer 15

Unsaturated chemical compounds with one or more planar rings of atoms joined by covalent bonds of different kinds.

Question 16

Carbonyl

Answer 16

A functional group of a carbon bound to a hydrogen, double bonded oxygen and an R group.

Question 17

What are the two types of carbonyl?

Answer 17

Ketone and Aldehyde

Question 18

Aldehyde

Answer 18

This is a carbon with an R group, hydrogen atom and a double bonded oxygen.

Question 19

Ketone

Answer 19

These are a carbon with one double-bonded oxygen and two R groups.

Question 20

What is the main reaction carbonyls go?

Answer 20

Nucleophilic attacks

Question 21

Nucleophilic Attack

Answer 21

This is where an electron rich species called a nucleophile, attacks an electron deficient species called an electrophile.

Question 22

What do carbonyl nucleophilic attacks form?

Answer 22

Hydroxyl groups.

Question 23

When do NA occur?

Answer 23

Another groups binds carbon, causing withdrawal of one of the electron pairs of the oxygen double bond, making it anioninc

Question 24

Why are aledhydes more reactive?

Answer 24

Steric effects and Electronic effects.

Question 25

Steric Effects

Answer 25

These are influences on a reaction course of a molecules due to occupying of space by atoms that disfavour/favour collision paths.

Question 26

How do aldehydes/ketone steric effects differ?

Answer 26

Aldehydes exerpeinces less steric hinderance as hydrogen is smaller

Question 27

How do aldehydes/ketone electrical effects differ?

Answer 27

Aldehydes have one less R group supplying partially postiive charge to the carbon with electrons, making the ketone carbon a weaker nucleus with less charge.

Question 28

What are the sources of metahne?

Answer 28

Wetlands,, termites, oceans, ruminants, landfills, energy and rice.

Question 29

What are methane sinks?

Answer 29

Soils and tropospheric OH, broken down by oxidation by hydroxyl radicals.

Question 30

How does methane slow down its own decomposition?

Answer 30

Removal of hydroxyl, as well as hydroxyl removal by carbon monoxide removing hydroxyl from wildfires

Question 31

Biogenic

Answer 31

Non-methane hydrocarbons of natural production like isoprene, producing ozone by photo-oxidation.

Question 32

Why are biogenic hydrocarbons highly reactive?

Answer 32

Containing of olfinic double bonds thus shorter lifetimes.

Question 33

What is isoprene released by?

Answer 33

Photosynthetic radiation

Question 34

Nitrous Oxide(N2O)

Answer 34

A colurless compounds emitted by soil bacteria.

Question 35

Nitrogen Dioxide(NO2)

Answer 35

Formed by high combustion by reaction of nitrogen in fuel and oxygen in the air.

Question 36

Where is nitrogen utilised?

Answer 36

Nitrogen fixation

Question 37

What are the two ways nitrogen is fixated?

Answer 37

Microorganisms conversion of N2 to ammonia/ammonium Atmospheric conversion of N2 by cosmic radiation or lightning forming nitrogen oxide.

Question 38

What are the two processes of the nitrogen cycle?

Answer 38

Nitrification and Denitrification

Question 39

Nitrification

Answer 39

Conversion of ammonia to NO2 and NO3 with N2O and NO byproducts

Question 40

Denitrificaiton

Answer 40

Conversion of soil nitrate to nitrogen gases like N2O and N2.

Question 41

What is denitrifciation performed by?

Answer 41

Bacteria using nitrate as a terminal electron acceptor in anaerobic conditions

Question 42

How much more powerful as a GHG is N2O?

Answer 42

300 TIMES

Question 43

What are the antrhopogenic sources of N2O?

Answer 43

Biomass burning, agriculture and degassing of irrigation water.

Question 44

What are the N2O sinks?

Answer 44

Stratospheric disassociation(90%) and reaction with oxygen.