Determination Of Total Hardness (CaCO3) and (MgCO3) of Well Water in Sampuabalo Village by Complexometry Titration Method

Abstract

Water has a very important role for humans in meeting daily needs, such as drinking, cooking, washing, transportation, agriculture, and industry. One of the properties of water that needs to be considered is disparity, which is a characteristic of water caused by the presence of divalent metal ions, such as calcium (Ca²⁺) and magnesium (Mg²⁺), which can react with soap and produce crust. In this study, the complexity titration method was used because it has an advantage in the quantitative analysis of metal ion levels in water samples. This method has high selectivity for metal ions, easy implementation, and good accuracy in measuring the total hardness of water. With the right indicators, the color change at the equivalent point can be clearly observed, thus providing reliable results in determining water hardness. This study aims to determine the total hardness of well water in Sampuanbalo Village using the complexity titration method. Samples were taken from three wells located in lowlands, temperate plains, and highlands. The results of the analysis showed that the total hardness level in the form of CaCO₃ in the samples of wells in the lowlands was 312 mg/L, 286 mg/L, and 332 mg/L. Meanwhile, in the wells in the lowlands, the modified CaCO₃ levels were 286 mg/L, the medium plains were modified 180 mg/L, and the highland was modified 266 mg/L. Meanwhile, The total hardness level in the form of MgCO₃ in lowland wells was 262.08 mg/L, medium plains 240.24 mg/L, and highlands 278.88 mg/L. In lowland wells modified MgCO₃ levels were 240.24 mg/L, medium plains modified 156.34 mg/L, and plateau modified 223.44 mg/L. Although cooked water showed a decrease in soberness levels, However, the nature of the hard water is still included in the category of hard water.