Question

How will you convert ethene to formaldehyde ?

Answer 1

Ethene can be converted into formaldehyde by the ozonolysis of the ethene followed by the hydration in presence of Zn and $H_{2}O$

$HC=CH\underset{\left(ii\right)Zn/H_{2}O}{\overset{\left(i\right)O_3}{\to }}\underset{formaldehyde}{2HCHO}$