Mechanism. This reaction is an example of electrophilic addition reaction and occurs in two steps: Step I. In the first step, a proton adds to form two possible carbocations (I and II). Since carbocation (I) is 3°, therefore, it is much more stable than carbocation (II) which is 1°,

Step II. In the second step, the Cl- ion readily attacks the 3° carboation (I) forming 2-chloro-2-methylpropane as the major product.

Increasing order of acidity is: ethanol < water < phenol. The phenoxide ion obtained after the removal of a proton is stabilised by resonance whereas the ethoxide ion obtained after the removal of a proton is destabilised by '+I' effect of C₂H₅ group. Therefore phenol is stronger acid than ethanol.

On the other hand ethanol is weaker acid than water because electron releasing -C₂H₅ group in ethanol increases the electron density on oxygen and hence the polarity of O-H bond in ethanol decreases. This results in the decreasing acidic strength. Hence acidic strength increases in the order given above.

Any strong oxidising agent such as acidified KMnO₄ or K₂Cr₂O_7.
\(\underset { Ethanol }{ CH_{ 3 }CH_{ 2 }OH\ } \overset { KMn{ O }_{ 4 }/\ { H }_{ 2 }{ SO }_{ 4 } }{ \underset { orK_{ 2 }{ Cr }_{ 2 }{ O }_{ 7 }\ /{ H }_{ 2 }{ SO }_{ 4 } }{ \longrightarrow }} \underset { EthanoIC\ acid }{ CH_{ 3 }COHH } \)

(a) It is due to more force of attraction between dispersed phase and a dispersion medium in lyophilic colloid than lyophobic colloid.
(b) Fe(OH) sol is positively charged which is /coagulated by negatively charged CI- ions present in sodium chloride solution.
(c) The sky appears blue in color due to scattering of light by colloidal particles. It is called Tyndall effect.

Due to high electronegativity (3·0) and small size of N, NH₃  forms H-bonds with water and hence it is water soluble. On the other hand, due to its lower electronegativity (2.1) of P and its bigger size than N, PH₃  does not form H-bonds with \({ H }_{ 2 }O\) . As a result, it does not dissolve  \({ H }_{ 2 }O\)  in and hence escapes as bubbles.

Animal hides are colloidal in nature and contain positively charged particles. Tannin contain negative charged colloidal particles. When hide is soaked in tannin, their mutual coagulation takes place and leather becomes hard.

Sulphides are not reduced easily but oxides are easily reduced.

(i) Order of reaction is zero.
(ii) Slope = -k
(iii) \(mol \ { L }^{ -1 }{ s }^{ -1 }\)

Anode : \(Cu\longrightarrow { Cu }^{ 2+ }+2{ e }^{ - }\) (Oxidation) 
Cathode : \({ Cl }_{ 2 }+2{ e }^{ - }\longrightarrow 2{ Cl }^{ - }\) (Reduction)

No (E_cell can be zero but not \({ E }_{ cell }^{ 0 }\) ). Further, \({ \Delta G }^{ 0 }=-nF{ E }_{ cell }^{ 0 }\) . As \({ E }_{ cell }^{ 0 }\neq 0\) ,therefore, \({ \Delta }_{ r }{ G }^{ 0 }\) also cannot be zero.

ZnO loses oxygen on heating and vacant sites of anions are occupied by electrons which absorb light fro the visible region and radiate complementary color, i.e. yellow.

In pure water, the entire surface is occupied by water are volatile. On adding glucose, some water molecules on the surface are replaced by glucose molecules which are non - volatile. Hence, vapour pressure is lowered.