Question

(i) How is methanal obtained from methanol?
(ii) Write the chemical equation of the reaction involved in the preparation of methanal from methanol.
(iii) Mention one test of an aqueous solution of methanal in the biology laboratory.
OR
Complete the following reaction equations:
(i) $CH_3 CH_2OH + 3O_2 \longrightarrow$
(ii) $HCHO + H_2 \longrightarrow$
(iii) $CH_3COOH + C_2H_5OH \longrightarrow$

Answer 1

Hey there
I DONT KNOW

Answer 2

1) Methanal is obtained from methanol by the process of dehydrogenation and oxidation.

2) The reaction takes place as follows

2CH3OH + O2 = 2HCHO + 2H2O

A mixture of methanol vapour and air at temperature 1000 K pressure more than atmospheric pressure is passed over finely powdered silver which is used as a catalyst. Molybdenum(VI) oxide is also used as it is inert. It is used as a fuel.

3) The aqueous solution of methanal is used for the preservation of human and animal specimens in bio laboratory. It is colourless and has a pungent smell.

OR

a)

CH3CH2OH + 3O2 =2CO2 + 3H2O

This is combustion reaction

b)

HCHO + H2 = CH3OH

This is decomposition reaction.

C) CH3COOH+ C2H5OH= CH3COOC2H5 + H2O

This is esterification reaction