A carboxylate is a salt or ester of a carboxylic acid. Carboxylate salts have the general formula M(RCOO)n, where M is a metal and n is 1,2,...; carboxylate esters have the general formula RCOOR`. R and R` are organic groups; R`≠H. A carboxylate ion is the conjugate base of a carboxylic acid, RCOO−. It is an ion with negative charge. == Res...... Found on http://en.wikipedia.org/wiki/Carboxylate