Q.

Which of the following properties is not true regarding organic compounds

1 They are generally covalent compounds.  
2 Show isomerism  
3 Compounds have high melting and boiling points  
4 Generally insoluble in water.  

Ans.

(3)

Organic compounds have low melting and boiling points because they are made of weak covalent bonds. Thus, the property which is not true regarding organic compounds is that they have high melting and boiling points.