Vardaan Learning Institute

Ans: (b) 3
n-Pentane, Isopentane, Neopentane.

Ans: (d) $C_4H_8$
$CH_4, C_2H_6, C_3H_8$ are Alkanes ($C_nH_{2n+2}$). $C_4H_8$ is an Alkene ($C_nH_{2n}$).

Ans: (c) Ketone
'-one' suffix indicates Ketone group (>C=O).

Ans: (d) They have strong forces of attraction between the molecules.
Carbon compounds (Covalent) usually have weak intermolecular forces, hence low boiling points.

Ans: (c) Sodium ethoxide and hydrogen
$2C_2H_5OH + 2Na \rightarrow 2C_2H_5ONa + H_2$.

Ans: (b) Neon
Carbon (2,4) shares 4 electrons to get 8 valence electrons, similar to Neon (2,8).

Ans: (a) Hydrophilic head and a hydrophobic tail
Head (Ionic end) is water loving (Hydrophilic), Tail (Hydrocarbon chain) is water repelling (Hydrophobic).

Ans: (b) $CH_2=CH_2 + H_2 \rightarrow CH_3-CH_3$
Addition of hydrogen to unsaturated hydrocarbon (Ethene) to form saturated hydrocarbon (Ethane).

Ans: (b) $CO_2$
Reaction produces brisk effervescence due to evolution of Carbon dioxide gas.

Ans: (a) Addition reaction
Addition of hydrogen across double bonds in unsaturated fatty acids.

Ans: (a) Both A and R are true and R is the correct explanation of A.
Due to energy considerations (cannot form $C^{4+}$ or $C^{4-}$), it shares electrons.

Ans: (c) A is true but R is false.
Vegetable oils contain long unsaturated carbon chains, which are healthy. Animal fats are saturated.

Ans: (a) Both A and R are true and R is the correct explanation of A.
Chemical analogues means chemically similar. Since both are carbon forms, they give CO2 on burning.

Ans: (a) Both A and R are true and R is the correct explanation of A.
It is a very good solvent, dissolving many organic compounds, hence used in medicines.

(i) (a) Methane: C shares 1 e- with 4 H atoms. (b) CO2: C shares 2 e- pairs with each O atom.
(ii) Catenation: Self-linking property. Carbon shows maximum due to small size and strong C-C covalent bond energy.

(i) Series of compounds with same functional group, similar chemical properties, differing by CH2 unit.
(ii) Same general formula; Difference in molecular mass is 14u.
(iii) Ethyne, $C_2H_2$ ($CH \equiv CH$).

(i) Substances capable of adding oxygen to others.
(ii) Alkaline KMnO4 or Acidified K2Cr2O7.
(iii) $CH_3CH_2OH + 2[O] \rightarrow CH_3COOH + H_2O$.

(i) Ethanoic acid: $CH_3-COOH$
(ii) Bromopentane: $C_5H_{11}Br$
(iii) Butanone: $CH_3-CO-CH_2-CH_3$
(iv) Hexanal: $C_5H_{11}CHO$

(i) Ethanol & Ethanoic Acid: Add Sodium Bicarbonate. Ethanoic acid gives brisk effervescence (CO2), Ethanol does not.
(ii) Soaps & Detergents: Shake with hard water. Detergent gives lather, Soap gives white curdy precipitate (scum).

(i) Alkanes: $C_nH_{2n+2}$, Alkenes: $C_nH_{2n}$, Alkynes: $C_nH_{2n-2}$.
(ii) Combustion: $CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O + Heat + Light$.

(i) Soap: Bio-degradable, Sodium salt of fatty acid. Detergent: Non-biodegradable, Sulphonic salt.
(ii) Micelle Formation: Hydrophobic tail attaches to dirt, Hydrophilic head remains in water. Agitation lifts dirt off.
(iii) Scum Formation: Calcium/Magnesium ions in hard water react with soap to form insoluble salt.

(i) Acid + Alcohol $\rightarrow$ Ester + Water. $CH_3COOH + C_2H_5OH \rightarrow CH_3COOC_2H_5 + H_2O$.
(ii) Saponification (with NaOH).
(iii) Used in making perfumes and flavouring agents due to sweet fruity smell.

(i) $C_nH_{2n}$
(ii) Graphite
(iii) Cyclohexane: Ring structure of 6 carbons with single bonds, each C attached to 2 H atoms. Formula C6H12.

X is $C_3H_6$ (Propene, Unsaturated). Y is $C_4H_{10}$ (Butane, Saturated).
Only Unsaturated compounds show addition reaction. Hence, X will show it.
Equation: $CH_3-CH=CH_2 + H_2 \xrightarrow{Ni} CH_3-CH_2-CH_3$.