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Alcohols and phenols react with highly electropositive alkali metals such as sodium, potassium etc to yield corresponding alkoxides/phenoxides and hydrogen. 2 R - OH + 2 Na ---------> 2 RONa (Sodium alkoxide) + H 2 2 C 2 H 5 OH + 2 Na ----------> 2 C 2 H 5 ONa (Sodium ethoxide)+ H 2 Related post Chemical properties of Alcohols and Phenols

Alkenes undergo hydration (addition of water across C=C bond) in presence of dilute H 2 SO 4 to produce alcohols. In the case of unsymmetrical alkenes, addition of water to the double bond is in accordance with Markownikoff’s rule. Industrially, the alkene obtained by cracking of hydrocarbons, is absorbed by passing it into sulphuric acid at k and atmospheric pressure. The acid is diluted and treated with steam to release the alcohol.

Alkyl halides are hydrolysed to the corresponding alcohols on boiling with aqueous alkali (NaOH or KOH) or moist silver oxide (Ag 2 O). RX + NaOH --------> R-OH + NaX CH 3 Br + NaOH -----------> CH 3 OH + NaBr Primary alkyl halides give a high yield of alcohols. But tertiary alkyl halides get dehydrogenated into alkenes. More Helpful article For YOU Preparation of alcohols from alkene by hydration Preparation of Alcohols from alkyl halides Preparation of Ethanol (Drinking Alcohol) Preparation of alcohols from Aldehydes and ketones Preparation of Methanol

Aldehydes and ketones are converted into alcohols by different methods, they are 1. Reduction 2. Using Grignard reagent Reduction Aldehydes and Ketones are reduced to the corresponding alcohols by 1. Addition of hydrogen in the presence of catalysts (catalytic hydrogenation), such as finely divided platinum, palladium, nickel and ruthenium 2. Treating aldehydes and ketones with chemical reagents such as sodium borohydride (NaBH4) or lithium aluminum hydride (LiAlH4). Aldehydes yield primary alcohols while ketones give secondary alcohols. R – CHO (Aldehyde) + H2 ----pd------> R CH2OH (primary alcohol) CH3CHO (Acetaldehyde) + H2 ----Ni------> CH3CH2OH (Ethanol) R CO R’ (Ketone) ----- 1.NaBH4 , 2.H2O ---> R – CH –R’–OH (secondary alcohol) UsIng Grignard reagent When Grignard reagent are treated with aldehydes or ketones, addition products (magnesium salt) are formed. These products on hydrolysis give alcohols. The overall result is to blind the alkyl group of Grignard reagent to ...

In alcohols, the oxygen of the -OH group is attached to sp 3 hybridised carbon by a sigma bond formed by the overlap of sp 3 hybrid orbital of carbon with an sp 3 hybrid orbital of oxygen. The figure shown below illustrates the bonding in methanol. The C-O-H bond angle in alcohol is slightly less than the tetrahedral angle (109 0 28). It is due to the repulsion between the unshared electron pairs of oxygen. In phenols, the –OH group is attached to sp 2 hybrid carbon of an aromatic ring. The C-O-H bond angle in phenol is 109 0 . The carbon-oxygen bond length (136pm) in phenol is slightly less than that in methanol (142pm). This is due to partial double bond character on account of the conjugation of unshared electron pair of oxygen with the aromatic ring. In ethers, the four electron pairs, ie; the two bond pairs and two lone pairs of electrons around oxygen are arranged approximately in a tetrahedral arrangement. The c-o-c bond angle (111.7 0 in methoxy methane) is slightly greate...

The pH of acidic and basic buffer can be calculated by Henderson – Hasselbalch equations. Consider an acidic buffer HA + A - HA H + + A - K a = [H + ] [A - ] / [HA] [H + ] = K a [HA]/[A - ] [H + ] = K a [acid]/[salt] There fore pH = -log[H + ] pH = pK a + log [salt]/[acid] when, [salt]/[acid] = 1 , pH = pK a Since pK a of an acid is a constant at constant temperature, the pH of the buffer is constant. Thus buffer capacity is maximum in a solution containing equivalent amount of acid and its salt. The pH of basic buffer is also given by Henderson – Hasselbalch equation BOH B + + OH - K b = [B + ][OH - ]/[BOH] [OH - ] = K b [BOH]/[B + ] pOH = pK b + log [salt]/[base] pH = 14 – pOH = 14 – [pK b + log [salt]/[base]]

The property of a buffer solution to resist change in its pH value even when small amounts of the acid or the base are added to it is called buffer action . Consider the acidic buffer solution containing acetic acid and sodium acetate. They dissociate as CH3COONa <=======> CH3COO - + H + CH3COONa <=======> CH3COO - + Na + When a few drops of an acid, HCl is added to this buffer solution, the H + ions combine with CH3COO - ions to form weakly ionized molecules of CH3COOH. CH3COO - + H + <=======> CH3COOH Thus H + ion concentration does not change and hence the pH of the solution remains constant. When a few drops of base, NaOH is added to the buffer solution, hydroxyl ions of the base neutralize the acid, forming salt and water. Similarly, in a basic buffer solution of NH4OH and NH4Cl, they dissociates as NH4OH <======> NH4 + + OH - NH4Cl ----------> NH4 + + Cl - When a few drops of a base added, the OH - ions given by it combine with NH4 + ions to ...