QUANTITATIVE DETERMINATION OF TOTAL HARDNESS IN DRINKING WATER BY COMPLEXOMETRIC EDTA TITRATION
Quantitative Determination of Total Hardness In Drinking Water By Complexometric EDTA Titration
R. A. J. Cadiz1 and J. M. Nael2
1Institute of Biology, College of Science
2National Institute of Geological Sciences, College of Science
University of the Philippines, Diliman, Quezon City, Philippines
Date Submitted: May 9, 2013
Abstract
This experiment is about the determination of water hardness through the use of complexometric EDTA titration. Determination of water hardness is important to find out the most suitable water hardness under particular circumstances. This was conducted for the purpose of applying the concept of complexometric titration using an efficient chelating agent, EDTA. Sample mineral water was analyzed using standard EDTA with EBT as indicator, and calcium ions present in the solution were calculated to determine the hardness of the water sample. At the end of the experiment, the results indicated that the mineral sample water has large amounts of calcium and magnesium ions—an implication of a hard water sample.
INTRODUCTION
Water hardness is a measure of the amount of calcium and magnesium present in sample water[1]. These calcium and magnesium ions have the capacity to replace sodium or potassium ions and form sparingly soluble products or precipitates.[2] Water hardness is involved in various aspects of industrial and biochemical processes. Large amounts of ppm CaCO3 in water can form precipitates when interacted with soap and form rings known as “scum” in several utensils and appliances. The formation of these “scum” in electrical appliances degrades its efficiency and will eventually reduce its life span. In addition, these can cause impairments on fabric as well, and damage water treatment plants and piping systems at a water hardness of 300 ppm CaCO3.[3] Calcium is necessary for aquatic animals such as fish. It serves an important role in bone formation, blood clotting, and metabolic processes of the fish and prevents the loss
R. A. J. Cadiz1 and J. M. Nael2
1Institute of Biology, College of Science
2National Institute of Geological Sciences, College of Science
University of the Philippines, Diliman, Quezon City, Philippines
Date Submitted: May 9, 2013
Abstract
This experiment is about the determination of water hardness through the use of complexometric EDTA titration. Determination of water hardness is important to find out the most suitable water hardness under particular circumstances. This was conducted for the purpose of applying the concept of complexometric titration using an efficient chelating agent, EDTA. Sample mineral water was analyzed using standard EDTA with EBT as indicator, and calcium ions present in the solution were calculated to determine the hardness of the water sample. At the end of the experiment, the results indicated that the mineral sample water has large amounts of calcium and magnesium ions—an implication of a hard water sample.
INTRODUCTION
Water hardness is a measure of the amount of calcium and magnesium present in sample water[1]. These calcium and magnesium ions have the capacity to replace sodium or potassium ions and form sparingly soluble products or precipitates.[2] Water hardness is involved in various aspects of industrial and biochemical processes. Large amounts of ppm CaCO3 in water can form precipitates when interacted with soap and form rings known as “scum” in several utensils and appliances. The formation of these “scum” in electrical appliances degrades its efficiency and will eventually reduce its life span. In addition, these can cause impairments on fabric as well, and damage water treatment plants and piping systems at a water hardness of 300 ppm CaCO3.[3] Calcium is necessary for aquatic animals such as fish. It serves an important role in bone formation, blood clotting, and metabolic processes of the fish and prevents the loss
References: [13] Whitten, K.[et. Al.], Chemistry.8th ed., Thomas Higher Education. USA. 2007, p. 742 [14] Skoog, D.A., West, D.M., et al., Introduction to Analytical Chemistry, 8th edition, Cengage Learning Asia Pte Ltd., 2012, p