<Dl> <Dd> C 6 H 4 (O H) 2 (a q) + H 2 O 2 (a q) ⟶ C 6 H 4 O 2 (a q) + 2 H 2 O (l) (\ displaystyle C_ (6) H_ (4) (OH) _ (2 (aq)) + H_ (2) O_ (2 (aq)) \ longrightarrow C_ (6) H_ (4) O_ (2 (aq)) + 2H_ (2) O_ ((l))) </Dd> </Dl> <Dd> C 6 H 4 (O H) 2 (a q) + H 2 O 2 (a q) ⟶ C 6 H 4 O 2 (a q) + 2 H 2 O (l) (\ displaystyle C_ (6) H_ (4) (OH) _ (2 (aq)) + H_ (2) O_ (2 (aq)) \ longrightarrow C_ (6) H_ (4) O_ (2 (aq)) + 2H_ (2) O_ ((l))) </Dd> <P> This reaction is very exothermic, and the released energy raises the temperature of the mixture to near 100 ° C, vaporizing about a fifth of it . The resultant pressure buildup forces the entrance valves from the reactant storage chambers to close, thus protecting the beetle's internal organs . The boiling, foul - smelling liquid is expelled violently through an outlet valve, with a loud popping sound . The beetles' glands store enough hydroquinone and hydrogen peroxide to allow the beetle to release its chemical spray roughly 20 times . In some cases this is enough to kill a predator . The main component of the beetle spray is 1, 4 - Benzoquinone, which is particularly irritating to the eyes and the respiratory system . </P> <P> The flow of reactants into the reaction chamber and subsequent ejection occur in a series of about 70 pulses, at a rate of about 500 pulses per second . The whole sequence of events takes only a fraction of a second . These pulsations are caused by repeated microexplosions which are the results of the continuous pressure on the reservoir and the oscillatory opening and closing of the valve that controls access to the reaction chamber . This pulsed mechanism is beneficial for the beetles' survival because the system uses pressure instead of muscles to eject the spray at a constant velocity, saving the beetle energy . Also, the reintroduction of new reactants into the vestibule where enzymes are stored, reduces the temperature of the chamber, thereby protecting the peroxidases and catalases from thermal denaturation . </P>

Why is the bombardier beetle not harmed by the chemicals it stores