Question

(a) What is the molecular formula and structure of the alcohol which can be thought to be derived from pentane ?
(b) Write the names of the following functional groups :

(c) What makes the candle flame yellow and luminous ?

Lakhmir Singh Chemistry Class 10

Answer 1

A)The general formula of alcohol series is: Cn H2n+1 - OH

Pentane means - carbon atoms are 5

Molecular formula is:

C5H11OH

Structure :

    H  H    H   H  H

     |      |    |     |   |

H- C  -C  -C-  C -C-OH

    |     |     |     |     |

    H  H   H    H   H

b) Write the names of the functional groups :

-CHO--- aldehyde

--OH-- alcohol

-COOH--- carboxylic acid

--x= halogens

c)What makes the candle flame yellow and luminous ?

If the oxygen supply is insufficient , then the fuel burns incompletely producing mainly yellow flame

The unburnt carbon particles produced due to the incomplete combustion of fuel produces yellow flame which produces light hence it is luminous.