Moved from here.
I inherited a sealed 55 gallon drum of 12½ Sodium hypochlorite that had been sitting outside in the sun for two years. The chlorine straight out of the barrel tested 0 PPM.
While we are on this subject, I manage the chemistry and infrastructure of five YMCA pools (three indoor and two outdoor) that collectively contain 800,000 gallons of water. I'm now buying all of my liquid chlorine in 55 gallon drums marked as 12½ Sodium hypochlorite. They were usually filled within 30 days prior to delivery and seem to be well above the advertised 12½%. I go through about six of these in an average month. I am not confident that the method I am using to test these barrels is accurate.
When I started, I put four drops of the material straight out of the drum into a gallon of distilled water, shook well, tested using my regular Taylor 1,2,3 reagents and doubled the PPM result to arrive at the % in the barrel. While this system seemed to work, I doubted its accuracy so I moved to a serial dilution method. Specifically, I put 1 ml of the material in the barrel into 199 ml of distilled water and mixed well. Then I took 1 ml of that solution and mixed it in with a fresh 199 ml of distilled water. That, I believe results in a 1:40,000 dilution. I test that and multiply the resulting PPM by 4. That method is telling me I'm getting more than 20% at the barrel level. I can tell you the the stuff straight out of the barrel burns your skin if not rinsed off within 30 seconds or so. Nothing from the pool or big-box store ever had that effect on me.
Would somebody who is better at math and chemistry than me check/correct my math or suggest a better method for testing my freshly opened barrels?
I inherited a sealed 55 gallon drum of 12½ Sodium hypochlorite that had been sitting outside in the sun for two years. The chlorine straight out of the barrel tested 0 PPM.
While we are on this subject, I manage the chemistry and infrastructure of five YMCA pools (three indoor and two outdoor) that collectively contain 800,000 gallons of water. I'm now buying all of my liquid chlorine in 55 gallon drums marked as 12½ Sodium hypochlorite. They were usually filled within 30 days prior to delivery and seem to be well above the advertised 12½%. I go through about six of these in an average month. I am not confident that the method I am using to test these barrels is accurate.
When I started, I put four drops of the material straight out of the drum into a gallon of distilled water, shook well, tested using my regular Taylor 1,2,3 reagents and doubled the PPM result to arrive at the % in the barrel. While this system seemed to work, I doubted its accuracy so I moved to a serial dilution method. Specifically, I put 1 ml of the material in the barrel into 199 ml of distilled water and mixed well. Then I took 1 ml of that solution and mixed it in with a fresh 199 ml of distilled water. That, I believe results in a 1:40,000 dilution. I test that and multiply the resulting PPM by 4. That method is telling me I'm getting more than 20% at the barrel level. I can tell you the the stuff straight out of the barrel burns your skin if not rinsed off within 30 seconds or so. Nothing from the pool or big-box store ever had that effect on me.
Would somebody who is better at math and chemistry than me check/correct my math or suggest a better method for testing my freshly opened barrels?
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