The Chemical Earth Notes (Preliminary)

8/18/2019 The Chemical Earth Notes (Preliminary)

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The Chemical

EarthContentsPure and Impure Substances.................................................................................2

Chemical Earth...................................................................................................... 2

Separating Techniques...........................................................................................3

Gravimetric Analysis..............................................................................................

Peri!dic Table.........................................................................................................

Particle "ature !# $atter........................................................................................%

Structure !# an At!m.............................................................................................%

Arrangement !# Electr!ns...................................................................................... %

C!valent C!mp!unds.............................................................................................&

I!nic C!mp!unds................................................................................................... &

$etallic '!nding.................................................................................................... &

C!mparis!n !# Pr!perties.......................................................................................(

Chemical )eacti!ns............................................................................................... *

+ec!mp!siti!n....................................................................................................*

Synthesis............................................................................................................*

,rganic Chemistry.................................................................................................*

Al-anes...............................................................................................................*

Al-enes...............................................................................................................

Al-ynes...............................................................................................................

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Pure and Impure Substances$atter can be divided int! t0! categ!ries1

Pure substances h!m!gen!us1 these can be divided int! t0! m!re

categ!ries Elements1 matter c!nsisting !# !ne type !# at!m

C!mp!unds1 matter c!nsisting !# t0! !r m!re types !# at!ms

elements b!nded t!gether Impure substances !r mi4tures1 these are a c!llecti!n !# substances

n!t b!nded t!gether5 these can be divided int! t0! m!re categ!ries1 6!m!gen!us1 uni#!rm c!mp!siti!n air and bl!!d

6eter!gene!us1 n!n7uni#!rm c!mp!siti!n r!c-s and s!up

Chemical Earth8ayers !# the Earth1

Crust

$antle

,uter c!re

Inner c!re

Spheres !# the Earth1

Atm!sphere1 8ayers !# gases surr!unding Earth mi4tures !# gases

6ydr!sphere1 $ass !# 0ater #!und !n5 under and !ver the sur#ace !#

the Earth mi4tures !# salts and 0ater

8ith!sphere1 ,uterm!st shell !# the Earth9 c!mprises !# the Crustand p!rti!n !# the upper mantle mi4tures !# elements and

c!mp!unds9 minerals and !res 'i!sphere1 Includes parts !# the atm!sphere5 hydr!sphere and

lith!sphere9 all the living matter mi4tures !# carb!n7c!ntaining

c!mp!und

2


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Separating Techniques :iltrati!n

)esidue1 s!lids le#t behind;remains:iltrate1


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Chr!mat!graphy

Gravimetric Analysis This is the pr!cess !# determining the

percentage c!mp!siti!n !# each substance in mi4tures. This is d!ne by

separating every substance and then 0eighing it t! c!mpare 0ith the

!riginal mi4ture t!tal 0eight.

Periodic TableAt!mic number1 "umber !# pr!t!ns and electr!ns in an at!m

=alence electr!n1 The number !# electr!ns present in the !uterm!st shell

!# an at!m

=alency1 The number !# electr!ns an at!m either needs t! l!se !r gain t!

c!mplete its !utm!st shell


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Particle Nature of atterAll matter is made up !# particles called at!ms. There are three states

matter can e4ist in1

In s!lids5 at!ms are pac-ed tightly t!gether in an !rderly array and

are held by very str!ng #!rces resulting in high melting p!ints and

b!iling p!ints In liquids5 at!ms can m!ve #reely9 the #!rce bet0een at!ms is less

str!ng In gases5 the at!ms have 0ea- #!rces bet0een them causing very

rapid rand!m m!ti!n 'r!0nian m!vement

A m!lecule is the smallest particle !# a substance that is capable !#

independent e4istence. E.g. an at!m !# ,4ygen is , 0here as a m!lecule

!# ,4ygen is ,2 because ,4ygen is a diat!mic m!lecule9 an substance

0hich e4ists in a m!lecule c!mp!sed !# t0! at!ms

S!me elements e4ist as p!lyat!mic m!lecules E.g. Ph!sph!rus P and

Sulphur S*

"!ble gases e4ist as independent at!ms i.e. 6elium e4ists as 6e and "e!n

e4ists as "e

Structure of an AtomAn at!m c!nsists !# a dense nucleus made up !# p!sitively charge pr!t!ns

and neutr!ns n! charge. A cl!ud !# rapidly m!ving negatively charged

electr!ns surr!und the nucleus. There are increasing energy levels as the

shells g! #urther a0ay #r!m the nucleus.

X Z A

A1 $ass number mass sum !# pr!t!ns and neutr!ns

>1 At!mic number number !# pr!t!ns

?1 Element

%


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Is!t!pes are at!ms !# the same element but 0ith di@erent mass numbers

due t! the di@erent number !# neutr!ns. E.g. Carb!n7/2 & neutr!ns and

Carb!n7/ * neutr!ns

Arrangement of ElectronsElectr!ns e4ist in discrete energy levels rst5 sec!nd5 third energy levels

and s! !n. Electr!ns in the !uter shells have higher energy than electr!ns

than inner shells.

nth energy level can acc!mm!date 2n2 electr!ns

The !ctet rule states that elements gain !r l!se electr!ns t! attain an

electr!n c!ngurati!n !# the nearest n!ble gas i.e. the !uterm!st shell

must acc!mm!date * electr!ns t! reach stable c!ngurati!n.

Covalent CompoundsC!valent c!mp!unds are #!rmed by sharing electr!ns bet0een at!ms !#

t0! !r m!re elements. "!n7metals usually #!rm c!valent c!mp!unds.

There are three types !# c!valent b!nds1

Single b!nds1 single pair !# electr!ns are

shared 62 +!uble b!nds1 t0! pairs !# electr!ns are

shared ,2 Triple b!nds1 three pairs !# electr!ns are

shared "2

In c!valent m!lecular c!mp!unds5 the #!rmula

represents the number !# at!ms !# each element in !ne m!lecule. E.g.

C,2 Carb!n di!4ide9 !ne carb!n at!m and t0! !4ygen at!ms

In c!valent net0!r-c!mp!unds5 at!ms are

c!valently b!nded in an

e4tended 3+ net0!r-. There

are n! individual m!lecules and

the #!rmula represents the rati! !#

the c!mp!nent at!ms in the

substance. E.g. C graphite !r

diam!nd

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Ionic CompoundsI!nic c!mp!unds are #!rmed 0hen at!ms l!se !r gain

electr!ns t! bec!me either cati!ns p!sitively charged

!r ani!ns negatively charged. Str!ng electr!static

#!rces all!0 the t0! !pp!sitely charged i!ns t! b!ndt!gether. I!ns are arranged in a regular 3+ lattice in an

i!nic s!lid thus i!nic c!mp!unds d! n!t e4ist as

m!lecules.

etallic !onding

Comparison of PropertiesProperty etals Ionic

Compounds

Covalent

olecular

Substances

Covalent

Net"or#

Solids$P$ and

!$P$

=ariable 6igh 8!0 6igh

Electrical

conductivit

y

G!!d G!!d

m!lten

P!!r P!!r

%ardnessand

alleability

6ard and$alleable

6ard but n!tmalleable

brittle

S!#t 6ard but n!tmalleable

brittle&orces

holding

particles

together in

the solid

+el!calised

electr!ns

Electr!static

#!rces

Interm!lecul

ar #!rces

C!valent

b!nding

thr!ugh!ut

the lattice

E'ample of

substance

$agnesium S!dium

chl!ride

Bater +iam!nd

(


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Chemical (eactionsA chemical reacti!n inv!lves rearrangement !# at!ms t! #!rm ne0

c!mp!unds

)ecomposition

This is a chemical reacti!n 0here a bigger c!mp!und brea-s int! t0! !r

m!re simpler substances. +ec!mp!siti!n can be d!ne by1

6eat1 CuC,3 brea-s int! a blac- c!mp!und Cu, and a gas C,2 Electricity1 62, can dec!mp!se int! elements 62 and ,2 by passing a

current thr!ugh it electr!lysis 8ight1 Silver salts dec!mp!se 0hen e4p!sed t! light. E.g. Ag'r

dec!mp!ses int! Ag and 'r2. This is used in ph!t!graphy

Synthesis

This is a chemical reacti!n 0here t0! !r m!re reactants #!rm !ne pr!duct9

c!mbinati!n reacti!n. E.g. "2 62 t! #r!m "63

*


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*rganic Chemistry This is a branch !# chemistry 0here it studies carb!n c!mp!unds.

6ydr!carb!ns are the c!mp!unds !# hydr!gen and carb!n. Pre4es1

/. $eth72. Eth73. Pr!p7. 'ut7%. Pent7&. 6e47(. 6ept7*. ,ct7. "!n7/D. +ec7

Al#anes These are saturated hydr!carb!ns 0here carb!n at!ms are lin-ed 0ith

single b!nds. E.g. $ethane C6

General #!rmula1C

n H

2n+2

Al#enes

These are unsaturated hydr!carb!ns 0here carb!n at!ms are lin-ed 0ith

d!uble b!nds. E.g. 'utene !r 'utylene C6*

General #!rmula1 C n H 2n

Al#ynes

These are unsaturated hydr!carb!ns 0here carb!n at!ms are lin-ed 0ith

triple b!nds. E.g. Pr!pyne C36

General #!rmula1C

n H

2n−2

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The Chemical Earth Notes (Preliminary)