Class X Science. Chapter 4.
Carbon and Its Compounds
---
Introduction: Carbon and Its Compounds
Carbon is one of the most important elements found on Earth. It forms the basis of all living organisms and plays a vital role in our daily life. From the food we eat to the fuels we use, most substances around us contain carbon. What makes carbon unique is its ability to form a very large number of compounds with itself and with other elements.
Carbon forms strong covalent bonds and can make long chains and complex structures. Because of this property, millions of carbon compounds exist, including fuels, medicines, plastics, soaps, detergents, and natural substances like proteins and carbohydrates. The study of these compounds is known as organic chemistry.
In this chapter, we study the nature of carbon, its bonding, important carbon compounds like hydrocarbons, alcohols, acids, soaps, and detergents, and their uses in everyday life. Understanding this chapter helps us see how chemistry connects closely with life and the environment.
---
100 Important Facts
1. Carbon is a non-metal with atomic number 6.
2. Carbon has four valence electrons.
3. The valency of carbon is 4.
4. Carbon forms covalent bonds by sharing electrons.
5. Carbon shows catenation, the ability to form long chains.
6. Strong carbon–carbon bonds make large molecules stable.
7. Organic compounds mainly contain carbon and hydrogen.
8. Diamond, graphite, and fullerene are allotropes of carbon.
9. Diamond is the hardest natural substance.
10. Diamond does not conduct electricity.
11. Graphite is soft and slippery.
12. Graphite conducts electricity due to free electrons.
13. Fullerene has a spherical cage-like structure.
14. Hydrocarbons contain only carbon and hydrogen.
15. Saturated hydrocarbons have single bonds only.
16. Alkanes are saturated hydrocarbons.
17. Unsaturated hydrocarbons contain double or triple bonds.
18. Alkenes contain a double bond.
19. Alkynes contain a triple bond.
20. Methane is the simplest hydrocarbon.
21. Ethane is the simplest alkane.
22. Ethene is the simplest alkene.
23. Ethyne is the simplest alkyne.
24. Homologous series is a group of similar organic compounds.
25. Members of a homologous series differ by –CH₂–.
26. Homologous series have similar chemical properties.
27. Functional groups determine chemical properties.
28. Alcohol functional group is –OH.
29. Carboxylic acid functional group is –COOH.
30. Aldehyde functional group is –CHO.
31. Ketone functional group is –CO–.
32. Ester functional group is –COO–.
33. Ethanol is a commonly used alcohol.
34. Ethanol is soluble in water.
35. Ethanol is used as fuel, solvent, and antiseptic.
36. Ethanol reacts with sodium to produce hydrogen gas.
37. Ethanoic acid is also called acetic acid.
38. Vinegar is dilute ethanoic acid.
39. Ethanoic acid turns blue litmus red.
40. Ethanoic acid reacts with sodium carbonate to give CO₂.
41. Esters are formed from alcohol and carboxylic acid.
42. Esterification requires an acid catalyst.
43. Esters have a pleasant fruity smell.
44. Saponification is the formation of soap.
45. Soap is made from fats and oils.
46. Soap molecules have two ends.
47. The hydrophilic end attracts water.
48. The hydrophobic end attracts oil or grease.
49. Soaps form lather easily in soft water.
50. Hard water contains calcium and magnesium salts.
51. Soaps form scum in hard water.
52. Detergents work in hard water.
53. Detergents do not form scum.
54. Carbon compounds are used as fuels.
55. Methane is a clean fuel.
56. LPG contains propane and butane.
57. Coal is a fossil fuel rich in carbon.
58. Petroleum is a mixture of hydrocarbons.
59. Natural gas is the cleanest fossil fuel.
60. Petroleum is refined by fractional distillation.
61. Petrol, diesel, and kerosene are petroleum products.
62. Petrochemicals are derived from petroleum.
63. Plastics are synthetic carbon compounds.
64. Polythene is a common plastic.
65. PVC is used for pipes and insulation.
66. Plastics are non-biodegradable.
67. Excess plastic causes environmental pollution.
68. Carbon compounds are essential for life.
69. Carbohydrates are carbon compounds.
70. Proteins are carbon compounds.
71. Fats are carbon compounds.
72. Enzymes are carbon-based molecules.
73. Carbon dioxide is produced during combustion.
74. Combustion of hydrocarbons releases heat energy.
75. Incomplete combustion produces carbon monoxide.
76. Carbon monoxide is a poisonous gas.
77. Alcohols burn with a clean blue flame.
78. Ethanol is added to petrol as biofuel.
79. Organic compounds show structural isomerism.
80. Covalent compounds have low melting points.
81. Covalent compounds are poor conductors of electricity.
82. Carbon forms single, double, and triple bonds.
83. Carbon compounds are used in medicines.
84. Many drugs are organic compounds.
85. Synthetic fibres are carbon compounds.
86. Nylon is a synthetic polymer.
87. Polyester is a carbon-based fibre.
88. Carbon compounds are used in dyes and paints.
89. Detergents are synthetic cleansing agents.
90. Soap is biodegradable.
91. Detergents are generally non-biodegradable.
92. Carbon compounds form the basis of organic chemistry.
93. Organic chemistry studies carbon compounds.
94. Carbon forms millions of compounds.
95. Carbon compounds show versatility.
96. Fossil fuels are limited resources.
97. Burning fossil fuels increases CO₂ level.
98. Increased CO₂ causes global warming.
99. Carbon cycle maintains balance in nature.
100. Carbon is called the backbone of life.
---