Page 43 - Chemistry ICSE Class X

Chemical Bonding 31
The oxidation and reduction are mutually dependent or reciprocal.
For example, during the formation of sodium chloride from sodium and
EJNQTKPG VJG HQNNQYKPI TGCEVKQP QEEWTU
ICKP QH GNGEVTQP reduction
^ŽŵĞ ŝŵƉŽƌƚĂŶƚ ĐŽŵŵŽŶ ŽdžŝĚŝƐŝŶŐ
+
Na + 1 Cl o Na + + Cl – o Na Cl – ĂŐĞŶƚƐ ĂƌĞ KdžLJŐĞŶ ;K Ϳ͕ KnjŽŶĞ ;K Ϳ͕
2 2 Ϯ ϯ
,LJĚƌŽŐĞŶ ƉĞƌŽdžŝĚĞ ;, O Ϳ͕ ŚůŽƌŝŶĞ
Ϯ Ϯ
NQUU QH GNGEVTQP oxidation ; ů Ϳ͕ EŝƚƌŝĐ ĂĐŝĚ ;,EK Ϳ͕ ŽŶĐ͘
ϯ
Ϯ
^ƵůƉŚƵƌŝĐ ĂĐŝĚ ;, SO Ϳ͕ WŽƚĂƐƐŝƵŵ
Ϯ
ϰ
What are oxidising and reducing agents ƉĞƌŵĂŶŐĂŶĂƚĞ ;<DŶK Ϳ͕ ĂŶĚ
ϰ
WŽƚĂƐƐŝƵŵ ĚŝĐŚƌŽŵĂƚĞ ;< ƌ O Ϳ͘
Ϯ
Ϯ ϳ
The substances (in the molecular or ionic form) which are capable of ͻ
oxidising other substances by CEEGRVKPI GNGEVTQPU from them are called &ůƵŽƌŝŶĞ ŝƐ ƚŚĞ ƐƚƌŽŶŐĞƐƚ ŽdžŝĚŝƐŝŶŐ
QZKFKUKPI CIGPVU. Thus, all chemical substances which can accept electrons ĂŐĞŶƚ ďĞĐĂƵƐĞ ŽĨ ŝƚƐ ŚŝŐŚĞƐƚ
HTQO QVJGTU CTG QZKFKUKPI CIGPVU. ĞůĞĐƚƌŽŶĞŐĂƟǀŝƚLJ͘
Strength of an oxidising agent depends upon the electronegativity of
the element. More electronegative elements are stronger oxidising agents. ^ŽŵĞ ŝŵƉŽƌƚĂŶƚ ƌĞĚƵĐŝŶŐ ĂŐĞŶƚƐ ĂƌĞ
The substances which can bring about reduction of other substances by ,LJĚƌŽŐĞŶ ;, Ϳ͕ ^ƵůƉŚƵƌ ĚŝŽdžŝĚĞ ;^K Ϳ͕
Ϯ
Ϯ
NQUKPI GNGEVTQPU to them are termed as TGFWEKPI CIGPVU. Thus, all chemical ,LJĚƌŽŐĞŶ ƐƵůƉŚŝĚĞ ;, ^Ϳ͕ ĂŶĚ
Ϯ
UWDUVCPEGU YJKEJ ECP NQUG GNGEVTQPU GCUKN[ CTG TGFWEKPI CIGPVU ĂƌďŽŶ ; Ϳ͘
ASSIGNMENT 2
Atoms and ions
ϭ͘ tŚĂƚ ŝƐ ƚŚĞ ĚŝīĞƌĞŶĐĞ ďĞƚǁĞĞŶ Ă ƐŽĚŝƵŵ ĂƚŽŵ ĂŶĚ Ă ƐŽĚŝƵŵ ŝŽŶ͍ tŝůů ƚŚĞŝƌ ƉƌŽƉĞƌƟĞƐ ďĞ ƚŚĞ ƐĂŵĞ Žƌ ĚŝīĞƌĞŶƚ͍
–
Ϯ͘ dŚĞ ĞůĞĐƚƌŽŶŝĐ ĐŽŶĮŐƵƌĂƟŽŶ ŽĨ ĐŚůŽƌŝĚĞ ŝŽŶ ; ů Ϳ ŝƐ ƚŚĞ ƐĂŵĞ ĂƐ ƚŚĂƚ ŽĨ ĂŶ ĂƌŐŽŶ ĂƚŽŵ͘ ^ŚŽƵůĚ ǁĞ ĐĂůů Ă ĐŚůŽƌŝĚĞ ŝŽŶ ĂƐ ĂŶ
ĂƌŐŽŶ ĂƚŽŵ͍
ϯ͘ tŚŝĐŚ ŽĨ ƚŚĞ ĨŽůůŽǁŝŶŐ ƐƵďƐƚĂŶĐĞƐ ĐŽŶƐŝƐƚ ŽĨ ŝŽŶƐ͍
ŵŵŽŶŝĂ͕ ƌŐŽŶ͕ WŽƚĂƐƐŝƵŵ ďƌŽŵŝĚĞ͕ ůƵŵŝŶŝƵŵ
ϰ͘ dŚĞ ĂƚŽŵŝĐ ŶƵŵďĞƌ ŽĨ ĐŚůŽƌŝŶĞ ŝƐ ϭϳ͘ ,Žǁ ŵĂŶLJ ĞůĞĐƚƌŽŶƐ ĂƌĞ ƚŚĞƌĞ ŝŶ ĐŚůŽƌŝĚĞ ŝŽŶ͍
ϱ͘ hƐŝŶŐ ƚŚĞ ĚĂƚĂ ŐŝǀĞŶ ďĞůŽǁ͕ ŝŶĚŝĐĂƚĞ ƚŚĞ ƐƉĞĐŝĞƐ ƚŚĂƚ ƌĞƉƌĞƐĞŶƚƐ ;ĂͿ Ă ĐĂƟŽŶ ;ďͿ ĂŶ ĂŶŝŽŶ ;ĐͿ ĂŶ ĂƚŽŵ͘

Number of
Species
protons neutrons electrons
A 9 ϭϬ ϭϭ
B ϭϳ ϭϴ ϭϳ
C 6 6 6

Chemical Bond

#VQOU JCXG EJGOKECN CHſPKV[ HQT GCEJ QVJGT 6JKU CHſPKV[ OCMGU VJG CVQOU
to combine together and form a large number of substances.

What is a chemical bond and how is it formed
# EJGOKECN DQPF OC[ DG FGſPGF CU the chemical force that keeps all the
CVQOU KP CP[ OQNGEWNG VQIGVJGT. dŚĞ ŶĂƚƵƌĞ ŽĨ Ă ĐŚĞŵŝĐĂů ďŽŶĚ
ĚĞƉĞŶĚƐ ƵƉŽŶ ƚŚĞ ǁĂLJ ƚŚĞ ĐŽŵďŝŶŝŶŐ
During bond formation, the combining atoms acquire stable electronic ĂƚŽŵƐ ĂĐƋƵŝƌĞ ƐƚĂďůĞ ĐŽŶĮŐƵƌĂƟŽŶƐ͘
EQPſIWTCVKQPU KP GKVJGT QH VJG HQNNQYKPI VJTGG YC[U
ƒ By transfer of electrons from the atom of an element to the atom of
another element. This gives rise to an ionic (electrovalent) bond.
ƒ By OWVWCN UJCTKPI of electrons. This gives rise to a covalent bond.
ƒ By QPG UKFGF UJCTKPI of the electrons. This gives rise to a coordinate
bond. This bond is also called as dative bond.