Principle of bleaching powder failure
Main composition is calcium hypochlorite bleaching powder, calcium hypochlorite with hundreds of CO2 and water vapor in the air to generate hypochlorous acid and calcium carbonate (the reaction degree of bleaching powder is in fact the work), if you don't use will be photolysis (long dark also reacts to) produce the oxygen and hydrogen chloride gas (known as acid or salt), then failed.
Step 1: Ca(ClO)2+H2O+CO2===CaCO3↓+2HClO
Step 2:2HCLO===2HCl+O2↑ exactly this step deactivates the bleaching powder
Industrial bleaching powder is chlorine gas with Ca(OH)2?
(rewrites the equation)
The bleach ingredient is
CaCl2· Ca (ClO) 2
1. Equation of bleaching powder's failure in air
2. Equation of excess CO2 into the bleach solution
3. Add dilute hydrochloric acid to the bleach solution
After the test found that bleaching powder powder powder open storage, the content of the effective component of chlorine will change, under normal circumstances, effective loss of chlorine within 9 days should reach more than 50%, after 18 days, basically has no disinfection effect.