Q72 of 312 Page 266

An organic compound A having the molecular formula C3H8O is a liquid at room temperature. The organic liquid A reacts with sodium metal to evolve a gas which bums causing a little explosion. When the organic liquid A is heated with concentrated sulphuric acid at 170 �C, it forms a compound B which decolourises bromine water. The compound B adds on one molecule of hydrogen in the presence of Ni as catalyst to form compound C which gives substitution reactions with chlorine.

(a) What is compound A?


(b) What is compound B?


(c) What type of reaction occurs when A is converted into B?


(d) What is compound C?


(e) What type of reaction takes place when B is converted into C?

(a) Compound A is propanol (CH3-CH2-CH2-OH)

(b) Compound B is propene (CH3-CH=CH2)


(c) Dehydration reaction


(d) Compound C is propane (CH3-CH2-CH3)


(d) Addition reaction



More from this chapter

All 312 →
70 Consider the following organic compounds:

CH3OH, C2HsOH, CH3COCH3, CH3COOH, C2H5COOH, C4H9COOC2H5, CH4, C2H6, CH3CHO, HCHO


Out of these compounds:


(a) Which compound is most likely to be sweet-smelling?


(b) Which compound on treatment with cone. H2SO4 at 170 �C forms an alkene?


(c) Which compound on repeated chlorination forms chloroform?


(d) Which compound is added to alcohol to denature it?


(e) Which compound is a constituent of vinegar?


(f) Which compound is used to sterilise wounds and syringes?

 71 An organic acid X is a liquid, which often freezes during winter time in cold countries, having the molecular formula C2H4O2. On warming it with methanol in the presence of a few drops of concentrated sulphuric acid, a compound Y with a sweet smell is formed.

(a) Identify X and Y. Also write their formulae showing the functional group present in them.


(b) Write a chemical equation for the reaction involved.

 73 An organic compound A (molecular formula C2H4O2) reacts with Na metal to form a compound B and evolves a gas which burns with a pop sound. Compound A on treatment with an alcohol C in the presence of a little of concentrated sulphuric acid forms a sweet-smelling compound D (molecular formula C3H6O2). Compound D on treatment with NaOH solution gives back B and C. Identify A, B, C and D. 74 Which of the following hydrocarbons can decolourise bromine water and which cannot? Why?

C6H12, C6H14, C6H10