<Tr> <Td> Esters </Td> <Td> </Td> <Td> R C--CO--O--CR </Td> <Td> </Td> <Td> Ethyl acrylate </Td> </Tr> <Tr> <Td> Carbonate esters </Td> <Td> </Td> <Td> R C--O--CO--O--CR </Td> <Td> </Td> <Td> Ethylene carbonate </Td> </Tr> <Tr> <Td> Ketones </Td> <Td> </Td> <Td> R C--CO--CR </Td> <Td> </Td> <Td> Acetone </Td> </Tr> <Tr> <Td> Aldehydes </Td> <Td> </Td> <Td> R C--CHO </Td> <Td> </Td> <Td> Acrolein </Td> </Tr>

What type of bond would exist between k and cl