Effect Of UV Rays On Pool Chlorine Biology Essay

Effect Of UV Rays On Pool Chlorine biological science EssayPools have always been a source of leisure for Australians. They ho using up enjoyment and good times for many ho enjoymentholds generated in a family or local swimming pocket billiards. Despite this, pocket billiardss have to be maintained by using chemicals or disinfectants, lest unwanted pathogens create health hazards. However, the everywhere use of these chemicals can also result in health hazards such as serious irritation and breathing problems. A balance or equilibrium, in that respectfore, must be achieved to maintain suitable conditions. This is where chemistry comes into play.The main type of chemicals utilise in pools to prevent unwanted pathogens is pool centiliter. atomic number 11 hypochlorite is a unremarkably utilize as pool chlorine. It was discovered by Louis Pasteur in the late(a) 19th century that atomic number 11 hypochlorite had disinfectant properties. sodium hypochlorite effectively kil ls bacteria, viruses and fungi. When pool chlorine is added to pee, a reaction takes place where hypochlorus acid is formed.In the past, more(prenominal) or less consumer chlorine bleach was sold in a 5.25% consequence. Today, some more c at one timentrated dissolvents are being sold and touted as an improvement over the less concentrated bleaches.To check for the intentness of the pool chlorine, excess honey oil iodide is to be added to it and and so it is to be titrated with a beginning of sodium thiosulfate. The assimilation of the liquid chlorine is then to be calculated using stoichiometry. The web ionic equations of the chemical reactions areSource alchemy In use Book 2There are also many factors that bushel the effectiveness of pool chlorine such as sun radiation.Ultra-violet (UV) bring down degrades hypochlorous acid to hydrochloric acid (HCl).Ultraviolet (UV) radiation not only destroys quit sensitive chemicals such as sodium hypochlorite (NaOCl), it also ha s the potential to importantly degrade the structural integrity of the storage tank or IBC containing the lighting sensitive material.According to the NSWMinistry of Health(2010) roughly 1/3 of free chlorine subject to UV lights in a outdoor swimming pool is destroyed every hour. UV light therefore lowers the parsimoniousness of the disinfection component of free chlorine.In this experimentation, the stringency of sodium hypochlorite in pool chlorine, left hand wing downstairs a UV lamps for polar periods of times, was metrical.Aim To check the effects of Ultra Violet (UV) rays on sodium hypochlorite (a bleaching agent used commonly in pools).2.0 Hypothesis As pool chlorine is left for longer periods of time beneath UV rays, the concentration of the pool chlorine will decrease.This was hypothesised as the theory mentions that UV rays degrade the component in pool chlorine which allows it to disinfect bacteria.3.0 Equipment/MaterialMaterialDiluted atomic number 11 hypo chloriteSodium thiosulfatePotassium iodideStarch indicatorBoiling wetEquipment2 x 100 mL Beaker5 x 250 mL Beaker15 x 100 mL Flask2 x 1L volumetric flaskfulful1 x 500 mL Volumetric flask1 x 100mL measure cylinder2 x 20mL Measuring cylinder3 x Funnel5 x 20 mL Pipette2 x 1mL Pipette3 x Stirring rodSenior BalanceBurette and standUV LampPermanent markerStopwatch4.0 SafetyTo prevent any ill-treat to the group during this experiment, safety precautions were taken to ensure the safety of the members. nurture to appurtenance A for MSDS (Material Safety Data Sheet).Lots of glassware was used end from holding too many pieces of glassware at once. Clean up glass immediately if any is broken.Handle boiling water with bursting charge Boiling water was used to create a solution of stiffen. Beaker pair of tongs were used to carry the boiling water.Potassium iodide is irritating to eyeball and bark Avoid contacting without gloves. Wash with water if contact occurs.Sodium thiosulfate is irritating to eyes and spit out Avoid contacting without gloves. Wash with water if contact occurs.Starch gives skin discomfort Avoid contacting without gloves.5.0 ProcedureRefer to Appendix 1 for forwardness of solutionsPreparation of titrationA burette and stand was filtered with the sodium thiosulfate solution.The burette was fill up up with the sodium thiosulfate solution to around the 0mL mark.100mL of diluted sodium hypochlorite was poured into 5 individual 250mL beakers.These beakers were labelled 0min, 15m, 30m, 1hr, 3hrs and 4hrs. totally the beakers, except the 0min beaker, were located under the UV lamp for the bills of time labelled on them. At this point the stopwatch was started, once the samples had reach the specified time they were taken out.For each time sample, 20mL was measured with a pipette and placed into 3 100mL flasks.10mL of potassium iodide solution and 2mL of starch indicator solution were prepared prior to every titration.TitrationThe mark of whe re the sodium thiosulfate solution in the burette was recorded before the titration occurred.10mL of potassium iodide solution was added to each time sample of 20mL sodium hypochlorite solution in the 100mL flasks. The mod solution was left until it has completed reacted (when the solution turns light yellow).The solution was then titrated until it turned a very pale yellow.2mL of starch indicator solution was added to the titrating solution. This should make the solution a dark blue/black colour.Titration proceed at a slower rate until the solution had turned clear. demean the finishing titre mark on the burette.These steps were repeated 3 times for each time sample ( be of 18 titrations).Figure 1 Diagram of titration in progress.6.0 Results remand 1 Table showing the amount of sodium thiosulfate solution added to sodium hypochlorite and potassium iodide solution at different times left under the UV ray.Refer to Appendix 2 for initial volume and final volume calculations and aver ages.Time (mins)Volume (mL) middling of 3 titrations023.351522.953022.516018.3518016.0324012.70Table 2 Table showing the concentration of pool chlorineRefer to appendix 3 for converting of average volume of titration to concentration.Amount of time left under UV lamp (mins)Concentration of OCl (M)00.03250150.03198300.03131600.025581800.022342400.01770Figure 1 Graph showing the concentrations of pool chlorine left under a UV lamp for different periods of time.7.0 DiscussionAn experiment design was made to test and compare the effects of UV rays on pool environments, particularly on the impacts of chlorine concentration. In doing this, a total of 18 pool chlorine samples were put under a UV lamp for different periods of time. The concentrations of the chlorine when left untouched by UV rays were inactive at around 0.03M. By exposing the pool chlorine samples to ultraviolet lights for attached periods of time, the concentration of the chlorine decreased. The graph shows that as the s odium hypochlorite is more overt to UV rays, the lower concentration of the pool chlorine was. A railway line of best fit was drawn to display the trend in the data. It showed that there is a linear relationship between the concentration and time left under a UV lamp. The data collected agrees with the theory that UV rays disrupt the structural integrity of the pool chlorine. The photodecomposition of chlorine is apparent as the initial levels of hypochlorite ion decreased by a significant amount when exposed to sunlight. The photochemical reaction that represents the situation of the experiment isThe main errors of the experiment were the inaccuracies of roughly aspects dealt with when implementing the experiment.One anomaly occurred when one sample of chlorine was left under the UV lamp for 60minutes. There is a major drop in concentration from 30min. This suggests that there was experimental error during the investigation.8.0 ConclusionThe results collected from this experiment suggest that the more pool chlorine is subject to UV lights, the lower the concentration of the chlorine will be. It has partially supported the hypothesisBibliographyDeb Smith, D. R. (2006). Chemistry in use Book 2. Sydney Queensland Chemistry syllabus.Date retrieved 05/09/12Fletcher, D. J. (N/D). (The Sodium Hypochlorite Story). Retrieved September 5, 2012, from south shore gunite pools http//www.southshoregunitepools.com/resources/htms/naocl.htmGina A. Ishida, B. . (N/D). IMPACT OF CHLORINE AND MONOCHLORAMINE ON ULTRAVIOLET. University of conjugation Carolina, Chapel Hill, NC N/A.Date retrieved 05/09/12N/A. (N/D, N/D N/D). Chlorination of pool water. Retrieved September 6, 2012, from pested http//www.pested.msu.edu/resources/bulletins/pdf/2621/e2621chap7.pdfN/A. (1968). Stabiliser (Cyanurate) Use in Outdoor Swimming Pools. Retrieved September 5, 2012, from NSW Government Health http//www.health.nsw.gov.au/utilities/copyright.aspAppendicesAppendix AGoing to add MSDS laterAppend ix 1Diluting sodium hypochlorite100mL of sodium hypochlorite was measured and put into a 1000mL volumetric flask.The flask was filled with distilled water up to the 1L markThe flask was inverted some(prenominal) timesSodium thiosulfate solution8.82g of sodium thiosulfate was placed into a 1L volumetric flashThe flask was filled with distilled water up to the 1L markThe flask was inverted several timesPotassium iodide solution5g of potassium iodide was weighed and placed into a 250mL beakerDistilled water was poured until it reached 105g on the scaleThe solution was thoroughly mixedStarch solution1g of starch indicator was weighed and placed into a 250mL beaker100mL of water was boiled and placed into the 250mL beakerThe solution was thoroughly mixed and was left to cool downAll solutions were labelled with the name of the solution, the concentration, a group members name and the teachers name.Appendix 2Initial volume and final volume of sodium thiosulfate left under a UV lamp at di fferent periods of time.0 min 23.35-0.04 15 min 45.63-23.29 30min 22.34-0.07= 23.31mL =22.34mL =22.27mL46.76-23.31 23.04-0.14 44.78-22.32= 23.45mL =22.90mL =22.46mL23.54-0.13 46.66-23.04 23.01-0.21=23.29mL =23.62mL =22.80mLAvg = = ==23.35mL =22.95mL =22.51mL60 min 41.22-23.01 3 hour 15.62-1.23 4hours 13.23-0.12=18.21mL =14.39mL =13.11mL18.62-0.33 30.59-15.62 26.35-13.23=18.29mL =14.97mL =13.12mL37.26-18.72 49.32-30.59 38.21-26.35=18.54mL =18.73mL =11.86mLAvg = ==18.35mL =16.03mL =12.70mL