( ( ( Formic acid ) ( -LRB- ( ( ( HCOOH , ) ( ( the substance ) ( ( causing ( ant bites ) ) ( to sting ) ) ) ) -RRB- ) ) ) ( ( is ( ( a ( weak acid ) ) ( with ( Ka ( of ( ( 1.8 x ) 10e-4 ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Formic) (NN acid)) (PRN (-LRB- -LRB-) (NP (NP (NNP HCOOH)) (, ,) (NP (NP (DT the) (NN substance)) (VP (VBG causing) (NP (NN ant) (NNS bites)) (PP (TO to) (NP (NN sting)))))) (-RRB- -RRB-))) (VP (VBZ is) (NP (NP (DT a) (JJ weak) (NN acid)) (PP (IN with) (NP (NP (NNP Ka)) (PP (IN of) (NP (QP (CD 1.8) (CD x)) (NNS 10e-4))))))) (. .)))
Formic acid (HCOOH, the substance causing ant bites to sting) is a weak acid with Ka of 1.8 x 10e-4.
(ROOT (S (NP (JJ Formic) (NN acid)) (VP (VBZ is) (VP (VBN found) (PP (IN in) (NP (NP (DT the) (NNS secretions)) (PP (IN of) (NP (JJ stinging) (NNS ants))))))) (. .)))