Q58 of 312 Page 243

Three organic compounds A, B and C have the following molecular formulae:

A) C4H8O2


B) C4H10O


C) C4H8O


(a) Which compound contains an alcohol group? Write its name and structural formula.


(b) Which compound contains a carboxyl group? Write its name and structural formula.


(c) Which molecular formula can represent an aldehyde as well as a ketone? Write the names and structural formulae of the aldehyde and ketone represented by this molecular formula.

(a) B; Butanol, C4H9OH


(b) A;Butanoic acid, C3H7COOH



(c) C; C4H8O Aldehyde: Butanal, C3H7CHO



Ketone: Butanone, CH3COCH2CH3




More from this chapter

All 312 →
56 An organic compound having the molecular formula C3H6O can exist in the form of two isomers A and B having different functional groups. The isomer A is a liquid which is used as a solvent for nail polish. The isomer B is also a liquid. An aqueous solution of one of the lower homologues of B is used for preserving biological specimens in the laboratory

(a) What is compound A?


(b) Write the electron-dot structure of A.


(c) What is compound B?


(d) Write the electron-dot structure of B.


(e) Name the lower homologue of compound B which is used in preserving biological specimens.

 57 A hard material X which is mined from the earth is used as a household fuel and also for the generation of electricity at Thermal Power Stations. A soft material Y is also used as a fuel in the form of candles. A gaseous material Z which occurs along with petroleum is increasingly being used as a fuel in running vehicles in its compressed form.

(a) What are materials, X, Y and Z?


(b) When materials X, Y and Z are burned separately:


(i) Which material burns by producing a yellow, luminous flame?


(ii) Which material ultimately bums without producing a flame?


(iii) Which material can bum in a gas stove by producing a blue flame?

 59 A colourless organic liquid X of molecular formula C2H4O2 turns blue litmus to red. Another colourless organic liquid Y of molecular formula C3H6O has no action on any litmus but it is used as a nail polish remover. A yet another colourless organic liquid Z of molecular formula C3H6O has also no action on litmus but it is used in tincture of iodine.

(a) Name the liquid X. To which homologous series does it belong? Give the name of another member of this homologous series.


(b) Name the liquid Y. To which homologous series does it belong? Write the name of another member of this homologous series.


(c) Can you name an organic compound having the same molecular formula as liquid Y but which belongs to a different homologous series? What is this homologous series?


(d) Name the liquid Z. To which homologous series does it belong? Write the name of another member of this homologous series.

 60 You are given an organic compound having the molecular formula C3H8• Give the name and formula of the compound formed:

(a) when one H atom of C3H8 is replaced by a Cl atom.


(b) when one H atom of C3H8 is replaced by OH group.


(c) when one H atom of C3H8 is replaced by a CHO group.


(d) when one H atom of C3H8 is replaced by a COOH group.


(e) when two H atoms joined to the middle carbon atom of C3H8 are replaced by one O atom.