Page 276 - Chemistry ICSE Class X

12 Organic Chemistry

Carbon
CONTENTS
Atomic symbol C Atomic mass 12.01 u
ͻ Organic chemistry and organic
compounds Atomic number 6 Melting point 3800 K
ͻ DŽĚĞƌŶ ĚĞĮŶŝƟŽŶ ŽĨ ŽƌŐĂŶŝĐ 'NGEVTQPKE EQPſIWTCVKQP K L Atomic radius 77 pm
2 4
chemistry
ͻ hŶŝƋƵĞ ;Žƌ ǀĞƌƐĂƟůĞͿ ŶĂƚƵƌĞ ŽĨ Carbon is an essential element in all organic compounds. It is a nonmetal.
carbon An atom of carbon has four electrons in its outermost shell. So, it lies in
ͻ dLJƉĞƐ ŽĨ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ Group 14 (or Group IVA) of the periodic table. It has two electronic shells
ͻ Structure and isomerism (K and L). So, it lies in the second period of the periodic table.
ͻ Structural isomerism
ͻ &ƵŶĐƟŽŶĂů ŐƌŽƵƉƐ
ͻ Homologous series History of Organic Chemistry
ͻ Hydrocarbons
DŽƌĞ ƚŚĂŶ ϮϬϬϬ LJĞĂƌƐ ĂŐŽ͕ ŵĂŶLJ ƉŚŝůŽƐŽƉŚĞƌƐ ƌĞĐŽŐŶŝƐĞĚ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ ĚŝƐƟŶĐƚ ĨƌŽŵ
ͻ ůŬĂŶĞƐ͕ ĂůŬĞŶĞƐ ĂŶĚ ĂůŬLJŶĞƐ ŝŶŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ ĂŶĚ ĐůĂƐƐŝĮĞĚ ƚŚĞŵ ŝŶƚŽ ƚǁŽ ĐůĂƐƐĞƐ͗
ͻ EŽŵĞŶĐůĂƚƵƌĞ ŽĨ ŽƌŐĂŶŝĐ Ö dŚŽƐĞ ŚĂǀŝŶŐ ǀĞŐĞƚĂďůĞ ŽƌŝŐŝŶ͕ ƐƵĐŚ ĂƐ ƐƵŐĂƌ͕ ŵŽůĂƐƐĞƐ͕ ĨĞƌŵĞŶƚĞĚ ůŝƋƵŽƌƐ͕ ĨƌƵŝƚ ũƵŝĐĞƐ͕ ĞƚĐ͘
ĐŽŵƉŽƵŶĚƐ͗ ŐĞŶĞƌĂů ƌƵůĞƐ ĨŽƌ /hW Ö dŚŽƐĞ ŚĂǀŝŶŐ ĂŶŝŵĂů ŽƌŝŐŝŶ͕ Ğ͘Ő͘ ŵŝůŬ͕ ŚŽŶĞLJ͕ ĨĂƚ͕ ĞƚĐ͘
nomenclature C.W. Scheele ;ϭϳϰϮʹϴϲͿ ŝƐŽůĂƚĞĚ ƐĞǀĞƌĂů ĂĐŝĚƐ ĨƌŽŵ ƉůĂŶƚƐ͘ A.L. Lavoisier (1743–94) in 1784
ͻ EĂŵŝŶŐ ĂŶ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚ ĨƌŽŵ ƐŚŽǁĞĚ ƚŚĂƚ Ăůů ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ ;ĂƐ ƚŚĞLJ ǁĞƌĞ ůĂƚĞƌ ĐĂůůĞĚͿ ĐŽŶƚĂŝŶĞĚ ĐĂƌďŽŶ͕ ŚLJĚƌŽŐĞŶ͕
ŝƚƐ ĨŽƌŵƵůĂ ŽdžLJŐĞŶ͕ ŶŝƚƌŽŐĞŶ͕ ĞƚĐ͘ /ƚ ǁĂƐ ůĂƚĞƌ ŽďƐĞƌǀĞĚ ƚŚĂƚ ǁŚŝůĞ ŝŶŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ͕ ƐƵĐŚ ĂƐ ƐŽĚŝƵŵ
ͻ ^ƚƌƵĐƚƵƌĂů ĨŽƌŵƵůĂ ĨƌŽŵ ƚŚĞ ŶĂŵĞ ĐŚůŽƌŝĚĞ͕ ĐĂŶ ďĞ ƐLJŶƚŚĞƐŝnjĞĚ ĚŝƌĞĐƚůLJ ĨƌŽŵ ƚŚĞŝƌ ĞůĞŵĞŶƚƐ͕ ƚŚĞ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ͕ ƐƵĐŚ ĂƐ ĞƚŚLJů
ŽĨ Ă ĐŽŵƉŽƵŶĚ ĂůĐŽŚŽů͕ ĐŽƵůĚ ŶŽƚ ďĞ ƐŽ ƉƌĞƉĂƌĞĚ͘
ͻ ůŬĂŶĞƐ dŚĞ ĐŽŵƉůĞdž ŶĂƚƵƌĞ ŽĨ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ ĂŶĚ ƚŚĞ ŽďƐĞƌǀĂƟŽŶƐ ŵĞŶƟŽŶĞĚ ĂďŽǀĞ ůĞĚ ƚŽ ƚŚĞ
ͻ Methane ĐŽŵŵŽŶ ďĞůŝĞĨ ƚŚĂƚ ƚŚĞ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ ǁĞƌĞ ƉƌŽĚƵĐĞĚ ƵŶĚĞƌ ƚŚĞ ŝŶŇƵĞŶĐĞ ŽĨ ƐŽŵĞ ŶĂƚƵƌĂů
ͻ Ethane ĨŽƌĐĞƐ ĐĂůůĞĚ vital forces͘ dŚŝƐ ůĞĚ ƚŽ ƚŚĞ vital force theory ĨŽƌ ƚŚĞ ĨŽƌŵĂƟŽŶ ŽĨ ŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚƐ
ŝŶ ƉůĂŶƚƐ ĂŶĚ ĂŶŝŵĂůƐ͘ Berzelius ǁĂƐ ŽŶĞ ŽĨ ƚŚĞ ƐƚƌŽŶŐ ƐƵƉƉŽƌƚĞƌ ƚŽ ƚŚŝƐ ƚŚĞŽƌLJ͘
ͻ WŚLJƐŝĐĂů ĂŶĚ ĐŚĞŵŝĐĂů ƉƌŽƉĞƌƟĞƐ ŽĨ
/Ŷ ϭϴϮϴ͕ Ă 'ĞƌŵĂŶ ƐĐŝĞŶƟƐƚ͕ F. Wöhler (1800–82) obtained urea (a typical organic compound and
ethane
ƉƌŽĚƵĐƚ ŽĨ ƚŚĞ ĂŶŝŵĂů ŵĞƚĂďŽůŝƐŵͿ ďLJ ŚĞĂƟŶŐ ĂŶ ŝŶŽƌŐĂŶŝĐ ĐŽŵƉŽƵŶĚ͕ ĂŵŵŽŶŝƵŵ ĐLJĂŶĂƚĞ Žƌ Ă
ͻ ůŬĞŶĞƐ
ŵŝdžƚƵƌĞ ŽĨ ĂŵŵŽŶŝƵŵ ƐƵůƉŚĂƚĞ ĂŶĚ ƉŽƚĂƐƐŝƵŵ ĐLJĂŶĂƚĞ͘
ͻ Ethene heat
ͻ ůŬLJŶĞƐ NH CNO o NH ͘ K͘E, 2
2
4
ammonium cyanate urea
ͻ Ethyne heat
ͻ Alcohols (NH ) SO 4 + 2KCNO o 2NH CNO + K SO 4
2
4 2
4
ammonium sulphate potassium cyanate
ͻ ^ƚƌƵĐƚƵƌĂů ĂŶĚ ĞůĞĐƚƌŽŶŝĐ ĨŽƌŵƵůĂĞ rearrangement
ŽĨ ƐŽŵĞ ĂůĐŽŚŽůƐ NH CNO o NH ͘ K͘E, 2
2
4
(heat)
ͻ Ethanol (Ethyl alcohol, C H OH) ammonium cyanate
2 ϱ
ͻ Carboxylic acids tƂŚůĞƌ ǁƌŽƚĞ ƚŽ ĞƌnjĞůŝƵƐ͕ “I must tell you that I can make urea without the need of a kidney of
any animal.” dŚŝƐ ƌĞĂĐƟŽŶ ŐŝǀĞ Ă ďŝŐ ďůŽǁ ƚŽ ƚŚĞ ǀŝƚĂů ĨŽƌĐĞ ƚŚĞŽƌLJ͘ /Ŷ ϭϴϰϰ͕ <ŽůďĞ ƉƌĞƉĂƌĞĚ ĂĐĞƟĐ
ͻ ƚŚĂŶŽŝĐ ĂĐŝĚ ;Žƌ ĂĐĞƟĐ ĂĐŝĚͿ
ĂĐŝĚ ĨƌŽŵ ŝƚƐ ĞůĞŵĞŶƚƐ ĂŶĚ ŝŶ ϭϴϱϲ͕ Berthelot ƐLJŶƚŚĞƐŝnjĞĚ ŵĞƚŚĂŶĞ͘
dŚƵƐ͕ ƚŚĞ ǀŝƚĂů ĨŽƌĐĞ ƚŚĞŽƌLJ ǁĂƐ ƌĞũĞĐƚĞĚ͕ ĂŶĚ ŝƚ ǁĂƐ ƌĞĐŽŐŶŝƐĞĚ ƚŚĂƚ Ăůů ĐŚĞŵŝĐĂů ĐŽŵƉŽƵŶĚƐ
ǁŚĞƚŚĞƌ ŽƌŐĂŶŝĐ Žƌ ŝŶŽƌŐĂŶŝĐ͕ ŚĂǀĞ ƚŚĞ ƐĂŵĞ ĐŚĞŵŝĐĂů ĨŽƌĐĞƐ ŽƉĞƌĂƟŶŐ ŝŶ ƚŚĞŵ͘
Organic Chemistry and Organic Compounds
Sulphuric plant extracts, milk, oils, fats, sugar, starch, gums, alcohol,
etc. were known to the ancient people. Beer was brewed as far back as
7000 B.C. In order to differentiate products having vegetable and animal
origin from those having mineral origin (nonliving source), a Swedish
EJGOKUV , , $GT\GNKWU Ō KP UWIIGUVGF VJG ENCUUKſECVKQP QH
all chemical compounds as: