In this experiment, the hardness of an unknown water sample will be determined. The calcium in the water will be measured by performing a titration with EDTA. Eriochrome Black T will be used as an indicator. Standardization of EDTA will be performed first and then the determination of calcium concentration.
Wahyu Ratnaningsih 1 Chelometric Titration: The Determination of Water Hardness and Water Filtration Things for the lab notebook and to be included in the lab report: Report the water hardness as ppm CaCO3 of a 50 ml water sample that required A ligand is a molecule or ion which possesses at least one position at which it can attach itself to a metal ion.
Ammonia is a common example. The NH3 molecule has a single point of coordination which is through its nitrogen atom. For this reason it is referred to as a unidentate or one "toothed" ligand. Other ligands can attach themselves to many different places: When the number of attachment points increases, the ligand effectively wraps itself around and "claws" itself to the ion.
When this happens, the complexing agent is called a chelate pronounced key-latewhich is derived from the Greek word for claw or hoof, representing the characteristics of the metal-ligand complex.
A very widely used complexing reagent for this type of titration reaction is ethylenediaminetetraacetic acid EDT A. For solubility reasons the disodium salt will be used in this experiment. EDTA complexes with the ions contributing to water hardness in a one-to-one stoichiometry.
Even though a ligand may attach itself to the metal ion many different places within the complex it does not affect the overall stoichiometry, which is what we really need to know to carry out the calculations.
In the case of EDTA it is not known with certainty whether it 2 attaches itself to the hard water metal ions at either four or six positions but it does not really matter because regardless of the number of points of attachment the stoichiometry is known to be one-to- one between the metal ion and the EDT A.
The procedure described below fulfills all of the requirements for a volumetric titration and is widely used for the routine determination of water hardness. Soft water does not contain any significant amounts of these ions. Around the globe, water hardness varies quite a bit.
People with medical intolerance to hard water may need to have a water treatment cartridge installed on their water supply to remove the hard water ions. We have all experienced the problems of hard water when using soaps.
When you take a shower and use a bar of soap, you will notice a scum or "ring" around the bathtub or the walls of the shower, which is a direct result of the formation of the insoluble calcium or other hard water metal ion salts of the fatty acids that occurred when the soap solution came in contact with the hard water ions.
Using sodium stearate as a typical soap molecule, it dissolves in water to form sodium and stearate ions. When hard water is used, the calcium ion reacts with the stearate ion and forms the slightly soluble compound calcium stearate, which has a solubility product constant Ksp associated with it so that an equilibrium condition is established.
The equation for the dissolving of calcium stearate in water is: For applications such as these, soap is replaced by a detergent, which is more expensive than soaps so their use has been restricted to applications where the problems of the soap scum warrant the additional expense.Determination of Water Hardness Using a Titrator.
Hands-On Labs, Inc. Version Lab Report Assistant. This document is not meant to be a substitute for a formal laboratory report%(2). · Water Density Lab Report Introduction: Introduction:(Background information) Water is the most abundant compound on the Earth, and covers about 70% of the Earth's surface.
What is Density? Density of water is the weight of the water per its unit volume. Some things that effect the density of water are temperature, and ph-vs.com://ph-vs.com Determination of the Hardness of Water One of the factors that establishes the quality of a water supply is its degree of hardness.
Hardness is defined as calcium and magnesium ion content. Since most analyses do not distinguish between Ca2+ and Mg2+. Experiment 8 Determination of Total Hardness of Water by Complexometric Titration Lab instructor-Andrew Cho William Parnell 4/11/ Abstract: The hypothesis for this experiment was to determine if complexometric titration technique can identify the total “hardness” of water through mathematical ph-vs.com://ph-vs.com /analyticalchemlablab-report//view.
· Soap test for water hardness is quite simple. All we need for this experiment is a test-tube with water sample and soap ethanol solution. Add a few drops of soap solution to the water sample. Seal the test-tube with a stopper and shake it ph-vs.com://ph-vs.com /ph-vs.com · CHEMICAL PRECIPITATION: WATER SOFTENING Submitted to: Dr.
Hashsham The acceptable water hardness range is between mg/L as CaCO 3. A water picking up minerals including calcium and magnesium, ions which produce hard water. (Water Review, Consumer report ph-vs.com~hashsham/courses/ene/docs/Water Softening ph-vs.com