Bleaching effect of traditional chlorine water device

(1) After introducing Cl2, it was observed that the dried red cloth strip did not fade from the gas container A, and it was concluded that the dried chlorine gas had no bleachability, so the answer was: the dried chlorine gas had no bleachability;

(2) From the fading of wet red cloth in cylinder B, it can be concluded that HClO can be bleached because chlorine reacts with water to generate Cl2+H2O? HCl+HClO, the generated hypochlorous acid is bleaching,

Therefore, the answer is: chlorine water is bleached; Cl2+H2O？ HCl+HClO；

(3) Cl2+H2O？ HCl+HClO indicates that hydrochloric acid and HClO are formed, so an experiment is designed to verify whether HCl has bleachability. The operation method is to drop hydrochloric acid on the red cloth strip to eliminate the bleachability of hydrogen chloride, which proves that the bleaching substance is hypochlorous acid, so the answer is: verify whether HCl has bleachability;

(4) Chlorine is toxic and cannot be discharged into the air. The function of NaOH solution is to absorb excess chlorine. Chlorine reacts with sodium hydroxide to produce sodium chloride, sodium hypochlorite and water. The chemical equation of the reaction is 2NaOH+Cl2═NaCl+NaClO+H2O, so the answer is 2 NaOH+Cl2 ═ NaCl+NaClO+H2O.