1. Carbon has 4 electrons in its outermost shell. It cannot lose 4 (too much
energy) or gain 4 (unstable). So it shares 4 electrons, showing tetravalency and forming
covalent bonds.
2. Diamond: Each C atom is sp$^3$ hybridized, bonded to 4
others in a 3D tetrahedral network. No free electrons → Does not conduct. Graphite: Each C
atom is sp$^2$ hybridized, bonded to 3 others in 2D layers. Free electrons in p-orbitals between layers →
Conducts electricity.
3. Isomers of Butane ($C_4H_{10}$): n-Butane (straight
chain) and Isobutane (branched). They have same molecular formula but different structures.
4. Ethyl alcohol ($C_2H_5OH$) has an $-OH$ group (alcohol). Dimethyl ether
($CH_3OCH_3$) has an $-O-$ linkage (ether). They have the same molecular formula ($C_2H_6O$) but different
functional groups, hence different properties. This is called Functional Group Isomerism.
5. Cooking flames should NOT be yellow. A yellow flame indicates incomplete
combustion, producing soot (Carbon) and Carbon Monoxide (CO), a toxic gas. The air holes of the burner
should be opened to allow more oxygen for complete (blue flame) combustion.
6. Catalyst used: Nickel (Ni) or Palladium (Pd).
7. Unsaturated vegetable oils (containing $C=C$ bonds) react with Hydrogen to
become saturated fats (Vanaspati Ghee).
8. This is an Addition Reaction. Hydrogen adds across the
double bond.
9. Vanaspati Ghee has a long shelf life (doesn't become rancid easily)
because saturated fats are more stable than unsaturated fats towards oxidation.
10. Ethanol is a depressant. It slows down the metabolic processes and the
nervous system.
11. Excessive consumption damages the liver (Cirrhosis), brain, and nervous
system.
12. Methanol consumption is dangerous. Even small amounts
(as low as 10 ml) can cause blindness and larger amounts can cause death.
13. Industrial ethanol is denatured by adding Methanol, Pyridine, or Copper
Sulphate to make it unfit for consumption.
14. Butanone ($CH_3COCH_2CH_3$) is a Ketone. IUPAC Name: Butan-2-one.
Functional Group: $\gt C=O$ (Ketone).
15. To distinguish between Ethanol and Ethanoic Acid: Add Sodium Bicarbonate
($NaHCO_3$). Ethanoic Acid will produce brisk effervescence ($CO_2$ gas). Ethanol will not react.
