(CH₃)₂C = C (CH₃)₂

trichloro methane

CH₃ CH (OH) CH₂CH₃
2R-OH+ 2Na ⟶ 2RONa + H₂ ↑
2 moles of alcohol gives 1 mole of H₂ which occupies 22.4 L at 273 K and 1 atm number of moles of alcohol
= 2 moles of R -OH/22.4L of H₂ x 560 ml
= 0.05 moles
No of moles = mass/molar mass = m/M
= 3.7/0.05 = 74 g mol^-1
General formula for (R-OH) Cn H_{2n + 1}OH
n(12) + (2n + 1) (1) + 16 + 1 = 74
14n = 74 - 18
14n = 56
n = 56/14 = 4
The  "2" alcohol which contains 4 carbon is CH₃ - CH (OH) CH₂ - CH₃

Mass = 0.44 g
No. of moles = Given Volume/Molar Volume = 112/22400
Molar Mass =  0.44/112 x 22400 = 88g
C_nH_2n+1 + OH = 88
12n+ (1)(2n+1) + 16 +1 = 88
14n + 18 = 88
14n = 88 - 18
n =70/14 = 5

                                                          Pentanoicacid

\(\underset {Phenol} {\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OH}}+\mathrm{Zn}(\text { dust }) \rightarrow \underset {benzene(A)} {\mathrm{C}_{6} \mathrm{H}_{6}}+\mathrm{ZnO}\)

In this reaction, phenol is first converted into sodium phenoxide which is more reactive than phenol towards electrophilic substitution reaction with CO₂, Treatment of sodium phenoxide with CO₂ at 400 K, 4-7 bar pressure followed by acid hydrolysis gives salicylic acid.

Yes, we can use nucleophiles such as NH₃, CH₃O^- for the nucleophilic substitution of alcohol.
Example
\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}+\mathrm{NH}_{3} \rightarrow \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NH}_{2}+\mathrm{H}_{2} \mathrm{O} \)
\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}+\mathrm{CH}_{2} \mathrm{~N}_{2} \rightarrow \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OCH}_{3}+\mathrm{N}_{2}\)

Acetaldehyde - CH₃-CHO

 

Ethers having same molecular formula, but alkyl groups attached to the oxygen atom are different. This phenomenon is known as metamerism.
Metamers of 2- methoxy propane
\(\mathrm{C}_{2} \mathrm{H}_{5}-\mathrm{O}-\mathrm{C}_{2} \mathrm{H}_{5}-\) diethyl ether 
\(\mathrm{CH}_{3}-\mathrm{O}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3}\) methyl n-propyl ether