Which one of the following formular does not represents an organic compound?

Which one of the following formulae does not represent an organic compound?

Which one of the following formula correctly represents the organic compound formed when 1,2- dibromoethane is heated with NaOH in ethanol solution ?

Which one of the following compounds does not exist?

Which one of the following does not represent a travelling wave?

Which one of the following does not represent Arrhenius equation?

Which one of the following does not represent a colloidal system?

Which one of the following does not represent Arrhenius equation?