Question

What is the common formula for aldehyde?

Answer 1

.....|| 
R - C - H is an aldehyde 

.....O 
.....|| 
R - C - R' is a ketone 

.....O 
.....|| 
R - C - OH is a carboxylic acid 

.....O 
.....|| 
R - C - O - R' is an ester 

.....O 
.....|| 
R - C - NH2 is an amide 

notice the similarities and differences?