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- 1. University Of Manitoba Alkalinity Lab :-02 Course code:- FOOD4260 Group: - 1 Submitted By Name: - Gursewak Singh UM ID: - 7876293 Department of FoodScience and Statistic Submitted To Name: - Dr. Chamila Nimalaratne Lecturer of FOOD4260 Department of FoodScience Submission Date:- 28 February 2022
- 2. Introduction: -Alkalinity isa boundary that is estimated on practically all ecological examples - drinking water, normal waters, dirtied waters, sewage, and modern squanders. Alkalinity alludes to the buffering limit of water tests and to their capacity to kill acidic contamination from precipitation or wastewater. For city sewage or modern squanders, how much alkalinity is significant in deciding the kind of treatment which ought to be utilized. (Water Science School , 2018) Alkalinity is essentially brought about by the presence of carbonate (C03 2-) and bicarbonate (HC03-) particles, despite the fact that hydroxide (OH-) particles may likewise contribute, particularly when there is modern contamination. (Nimalaratne, 2022). Living organic entities, for example, amphibian life, work best in a pH scope of 5.0 to 9.0 and levels of 20 to 200 mg/L are average alkalinity values for new water. (Environmental Geochemistry, 2008). Whenever the pH is above 8.3, carbonate (CO3 2-) is the essential supporter of alkalinity; when the pH is beneath 8.3, bicarbonate (HCO3-) turns into the ruling component.
- 3. (Environmental Geochemistry, 2008).The upsides of alkalinity are accounted for in units of "mg CaCO3/L". (Nimalaratne, 2022). Now, if we talk about titration process that is the process that is very common to understand and know the presence of ion in our sample. We use four different such as tap water, bottled water and two unknown samples and two different end point by using the two different indicators such as phenolphthalein which will show the presence of hydroxide and carbonate ion, bicarbonate and bromocresol which helps to show the presence of bicarbonate ion in your sample and give us the total alkalinity of our sample. The primary goal of this lab was to identify the phenolphthalein alkalinity and total alkalinity of the given samples and also, give a chance the understand the most common and old technique of titration.
- 4. Methods and Material:- (Nimalaratne,2022) All the material and methods of doing experiment is mentioned in the lab manual. We can follow it by step by step to get best result. In sample, we are using tap water, bottled water and two unknown sample that are given by the lab coordinator. In the similar way for equipment, we are using Burette with burette stand, Erlenmeyer flask 100 or 250 ml, Beakers, Small short stem funnel, Graduated cylinders. In chemical, standard hydrochloric acid 0.02 N, Phenolphthalein indicator, Bromocresolgreen indicator, Distilled water and unknown sample. We follow whole process of acid content of food that mentioned in the lab manual. So, there is not valid modification that we applied in the process.
- 5. Results : - Table1 : - It is showing the raw data results that we collectedfromdifferent samples from the experiment. (Nimalaratne,2022) Sample Name /Number Sample Size Initial reading First indicator ( end point) Second indicator ( END POINT) Tap water 100ml 100ml 0 0 0 0 9ml 10.5 ml Bottledwater 100 ml 100ml 0 0 0 0 6 ml 7.5 ml Unknown 1 10 ml 10ml 0 0 22.5 ml 23.4 ml 23.5 ml 24.9 ml Unknown 3 10ml 10ml 0 0 10.5ml 8.9ml 21 ml 19.4 ml
- 6. Table 2: -The table is showing the result of HCl Used in Phenolphthalein alkalinity and HCl usedin total alkalinity of tap water and phenolphthalein alkalinity and total alkalinity inmg CaCO3/L for tap water sample. Sample Sample size Amount usedof HCL for Phenolphthalein alkalinity Amount usedof HCL for total alkalinity Phenolphthalein Alkalinity ( mg caco3/L Total alkalinity ( mg Caco3/ L Tap water 1 100 ml 0 9ml 0 90 Tap water sample 2 100ml 0 10.5 ml 0 105
- 7. Table 3: -The table is showing the result of HCl Used in Phenolphthalein alkalinity and HCl usedin total alkalinity of tap water and phenolphthalein alkalinity and total alkalinity inmg CaCO3/L for bottledwater sample. Sample Sample size Amount usedof HCL for Phenolphthalein alkalinity Amount usedof HCL for total alkalinity Phenolphthalein Alkalinity (mg caco3/L Total alkalinity (mg Caco3/ L Bottled water 1 100 ml 0 6 ml 0 60 Bottled water sample 2 100 ml 0 7.5 ml 0 75
- 8. Table 4: -The table is showing the result of HCl Used in Phenolphthalein alkalinity and HCl usedin total alkalinity of tap water and phenolphthalein alkalinity and total alkalinity inmg CaCO3/L for unknown sample 1. Sample Sample size Amount usedof HCL for Phenolphthalein alkalinity Amount usedof HCL for total alkalinity Phenolphthalein Alkalinity ( mg caco3/L Total alkalinity ( mg Caco3/ L Unknown 1 sample 1 10 ml 22.5 ml 23.5 ml 2250 2350 Unknown 1 sample 2 10ml 23.4 24.9 2340 2490
- 9. Table 5: -The table is showing the result of HCl Used in Phenolphthalein alkalinity and HCl usedin total alkalinity of tap water and phenolphthalein alkalinity and total alkalinity inmg CaCO3/L for unknown sample 3. Sample Sample size Amount usedof HCL for Phenolphthalein alkalinity Amount usedof HCL for total alkalinity Phenolphthalein Alkalinity ( mg caco3/L Total alkalinity ( mg Caco3/ L Unknown 3 sample 1 10ml 10.5ml 21 ml 1050 2100 Unknown 3 sample 2 10 ml 8.9 ml 19.4 ml 890 1940
- 10. Sample calculation: - PhenolphthaleinAlkalinity For unknown 3 : mg CaCO3/L = (V1 x N x 50 000)/ ml So we are know the V1 = 10.5 ml that is used in phenolphthalein alkalinity And Sample = 10 ml So, mg CaCo3/L = ( 10.5 * 0.02 N* 50000)/10 ml Mg CaCo3/L = 1050 mg CaCo3/L TotalAlkalinity For unknown3 : - mg CaCO3/L = (V2 x N x 50 000)/ ml So we are know the V2 = 21 ml that is used in phenolphthalein alkalinity And Sample = 10 ml So, mg CaCo3/L = (21ml * 0.02 N* 50000)/10 ml Mg CaCo3/L = 2100 mg CaCo3/L
- 11. Discussion:- Our most ofwater sample shown in the table 2 and table 3 which are normal tap water and bottled water. They do not have phenolphthalein alkalinity means they do not contain the carbonate ion and hydroxide in the sample. So, this is the major reason we did not notice any colour change at first step but if we talk about total alkalinity then we noticed the change to blue, which means we have bicarbonate ion present in both samples. After titration process,we got light yellow color which means we remove all alkalinity ion from the sample or maintain the pH of our water sample. There is theory behind why we did not notice any color change from water sample that is the sample is remains colorless throughout the range of acidic pH levels but begins to turn pink at a pH level of 8.2 and continues to a bright magenta at pH 10 and above. (Kozlowski, 2020). If hydrogen ions (H+, as found in an acid) were added to the pink solution, the equilibrium would switch, and the solution would be colorless. Adding hydroxide ions (OH-, as found in bases)will change the phenolphthalein into its ion and turn the solution pink. (Kozlowski, 2020). This is the same what happened with us that our sample already contain the hydroxide ion when we added indicator it reacts and did not show any colour change. If we talk about our unknown sample (table 4 and table 5) then we all got phenolphthalein color and bromocresolcolor, which means we got
- 12. all three ionwhich carbonates ion, hydroxide ion and bicarbonate ion in our unknown sample. Secondly, now if we talked about phenolphthalein alkalinity and total alkalinity, then in table 2 and table 3 we did not get any color change which means our phenolphthalein alkalinity is shown zero and, but we got some amount of total alkalinity because of presence of bicarbonate ion or bromocresolcolor change. If we talk about unknown sample 1 and 3 (table 4 and table 5) then we got high amount of phenolphthalein alkalinity and total alkalinity. Which is higher as compared to water sample alkalinity. Which means our unknown have higher pH as compared to water sample and take more amount HCl in the titration. Regardless of the starting pH, the higher the alkalinity of the water source, the more acid is required to reduce pH to 5.0. (Buechel, 2021). As we perform our experiment in lab, the initial step of the titration is the addition of few drops of the phenolphthalein indicator and started performing the titration process until you notice the colour change from light pink to clear ( transparent) and then for the total alkalinity, add some drops ofbromocresolindicator in the same sample and continue doing the titration process until you notice the colour change from green to light yellow or pale yellow. There might be some error in the experiment that we have number of solutions which can create problem or confusion to identify which one is which solution.
- 13. Also, sometimes wedid not properly know which is the end point of the process. So, we add extra amount of HCL, and which change our final results. Conclusion:- In conclusion, we can say that the titration process is properly done and successful and learned about how total alkalinity and phenolphthalein alkalinity of water sample and given unknown samples. Firstly, bicarbonate ion, hydroxides and carbonate ions is very important in to understand our alkalinity. We measure our all objectives in our process, so we lead to our final product. Moreover, everybody should know their process well to get the correct final product. Reference :- Works Cited (n.d.). Nimalaratne, C laboratory manual winter term 2022, water mangemnt in food process.food4260. Buechel, T. (2021, 11 09). water aklanity vs pH in your growing pedium-whatis the relationship between Acid used and alkalinity . Retrieved from PROMIX: https://www.pthorticulture.com/en/training-center/water- alkalinity-vs-ph/ Environmental Geochemistry. (2008, 10 17). Sciecne direct . Retrieved from Alkalnity an overview / ScienceDirects overviews :
- 14. https://www.sciencedirect.com/topics/earth-and-planetary- sciences/alkalinity Kozlowski, R. (2020,02 16). sciencing . Retrieved from why does phenolphthalein colour change : https://sciencing.com/phenolphthalein-change-color- 5271431.html Water Science School. (2018, 08 August ). UGSG science for changingworld . Retrieved from alkalnity and water/ US geological survey : https://www.usgs.gov/special-topics/water-science-school/science/alkalinity- and-water