Write a method for the preparation of aldehydes and ketones by the dehydrogenation of alcohols.

(N/A) This method is suitable for volatile alcohols and is of industrial application. In this method,alcohol vapors are passed over heavy metal catalysts ($Ag$ or $Cu$) at $573 \ K$.
$1^{\circ}$ Alcohols give aldehydes:
$RCH_2OH \xrightarrow{Cu, 573 \ K} RCHO + H_2$
Example: $CH_3CH_2OH \xrightarrow{Cu, 573 \ K} CH_3CHO + H_2$
$2^{\circ}$ Alcohols give ketones:
$R-CH(OH)-R' \xrightarrow{Cu, 573 \ K} R-CO-R' + H_2$
Example: $CH_3-CH(OH)-CH_3 \xrightarrow{Cu, 573 \ K} CH_3-CO-CH_3 + H_2$