Lab: Determination of Water Hardness by TitrationWater hardness is a measure of the amount calcium ion present in a water sample. Well water often has high concentrations of calcium as a result of the water dissolving calcium containing minerals from rocks in contact with the water. In this lab, you will perform several titrations on hard water, tap water and “soft” water samples. It will illustrate the concepts of stoichiometry, molar mass, solution calculations and titration.


View theDetermination of Water Hardness by Titration power point attached below, and watch the video to see what to expect as you perform the titrations in this lab.This will provide you with the necessary foundation for successfully completing the lab.Video on Titration Procedure:https://www.youtube.com/watch?v=bGh6Y02YFCw



Note:While you work on the lab,you are required to take certain images/photos of your labto document that you actually completed the lab yourself. Each photo should include anote card or a piece of paper with your name, the date you completed the experiment and your course section numberclearly visible.

Note Card Information:

My Name: Zack Aldawoody

Section Number: 145454

Download the item:Determination of Water Hardness Lab
Report attached below. This is what you will submit for grading. You can type your results and insert your images into this document.

Introduction to Graphing Determination of Water Hardness by Titration Lab CHEMISTRY 111 Overview •Practice a simple titration procedure. •Utilize titration to determine the calcium ion concentration in a water sample. •Determine the efficacy of an ion exchanger to remove calcium ions. •Perform calculations using stoichiometric and solution concepts. Materials Needed •Printed materials and basic materials needed from the kit: • Printed Investigation Manual • Printed Lab Report • Safety goggles • Gloves • Apron Materials Needed Additional materials needed from the kit: • Calmagite indicator • EDTA solution • pH 10 buffer capsule • Hard water mix • Ion Exchange resin • 10 mL Syringe • 1 mL Syringe • Cotton ball • Metal washer • Plastic mini-spoon Materials Needed Additional materials needed from the kit: • 10-mL graduated cylinder • 50-mL graduated cylinder • 25-mL Erlenmeyer flask • Grease pencil • Weighing boat • 250-mL beaker • 4 -10 oz plastic cups • 3 -1.25 oz plastic cups • 5 disposable pipets Materials Needed Needed but not supplied with the kit: • Distilled (or filtered) water • Paper towel • Plain white paper • Tap water Prior to the Lab/Safety •Carefully review the entire Investigation Manual, including the Overview and Objectives, Background information, necessary materials, safety precautions, lab preparation and procedures for all activities, and the waste disposal and clean-up information. •Make sure your work area is clean and out of the reach of pets and children. •Put your safety goggles on, and be sure to leave them on for the entire experimental procedure. Special Safety Precautions •The Calmagite solution may stain skin or clothing. •If exposed, immediately rinse with water to minimize possible staining. Do not ingest any of the materials Wash hands thoroughly Preparation – Lab Tips •Be sure to label all the cups to avoid confusion between the hard water, tap water, soft water, and pH 10 solutions. •When preparing the “Endpoint” sample, you MUST use either distilled water or filtered water. Tap water will not give the correct color when indicator is added. The purple (left) or blue (right) colors above are acceptable for the “Endpoint” solution. The solution to the right shows the initial color of the indicator. Activity 1 – Lab Tips •After pulling liquid into the syringe, hold the open end upward and expel any air bubbles. •Read the volume on the syringe from the flat portion of the plunger closest to the liquid. •Volume should be read to two places after the decimal (0.XX) •Practice forming one drop at a time. Activity 1 – Lab Tips •Make sure to have a white background under the flask to see the colors easily. •When you begin the titration, add ONE drop, then mix, then add the next drop and mix. •Look for a purple color when almost complete •Usually one more drop will cause color to change from purple to blue Starting Color Almost to Endpoint At Endpoint Images/Photos As you complete this lab, please capture images of the following steps of the lab procedure to include in your submitted lab report. ◦ Image 1: Endpoint comparison cup (See Page 10, Step 5) ◦ Image 2: Hard water + pH10 + indicator solution before titration (See Page 11, Step 5) ◦ Image 3: Hard water + pH10 + indicator solution after titration (See Page 11, Step 11) For each image you capture, include a card with your name, the appropriate date and section number written on it. This card must be visible in each image you submit with your lab report. Failure to include these images or the card with the image will result in a grade of zero for the submitted lab. Clean Up •Clean up any spills and dispose of the solutions and ion exchange column as directed in the Disposal and Cleanup section of the Investigation Manual (see page 13). •Clean and dry all equipment used. •Place your equipment and supplies back into their safe storage location until you need them again. •Clean and disinfect all surfaces used. •Thoroughly wash your hands. Determination of Water Hardness by Titration Lab Report Activity 1: Complexometric Titration (1 point) Calculation Examples On a clean sheet of paper, clearly show the following four calculations using your data for Hard Water Trial 1. Write your name, the correct date and the section number on the paper. Take a photo of your calculations and insert it in the box below. (Calculations 2 and 4 are found on Page 6, Equation 6 of the Investigation Manual.) 1. Volume of EDTA Consumed (mL) Calculation 2. Moles of CaCO3 Calculation 3. Molarity (M = ) of CaCO3 Calculation 4. Water Hardness ppm CaCO3 (mg/L) Calculation Repeat the calculations for all remaining Hard Water, Tap Water and Soft Water Trials, but you do not need to include images of this work. Data Tables (1 point) Complete the information below based on Data Table 1: Complexometric Titration of Hard Water in the Investigation Manual with the measured and calculated values for each Hard Water Trial. Hard Water Sample Hard Water Trial 1 Hard Water Trial 2 Hard Water Trial 3 Initial EDTA Syringe Reading (mL) 0.000.000.00 Final EDTA Syringe Reading (mL) 0.000.000.00 Volume of EDTA Consumed (mL) (initial – final reading) 0.000.000.00 Moles of CaCO3 in Sample 0.00 x 100 0.00 x 100 0.00 x 100 Molarity of CaCO3 in Sample (M = mol/L) 0.00 x 100 0.00 x 100 0.00 x 100 Water Hardness ppm CaCO3 (mg/L) 000000000 Average Hardness for 3 Trials 000 (2 points) Complete the information below based on Data Table 2: Complexometric Titration of Tap Water in the Investigation Manual with the measured and calculated values for each Tap Water Trial. Tap Water Sample Tap Water Trial 1 Tap Water Trial 2 Tap Water Trial 3 Initial EDTA Syringe Reading (mL) 0.000.000.00 Final EDTA Syringe Reading (mL) 0.000.000.00 Volume of EDTA Consumed (mL) (initial – final reading) 0.000.000.00 Moles of CaCO3 in Sample 0.00 x 100 0.00 x 100 0.00 x 100 Molarity of CaCO3 in Sample (M = mol/L) 0.00 x 100 0.00 x 100 0.00 x 100 Water Hardness ppm CaCO3 (mg/L) 000000000 Average Hardness for 3 Trials 000 Activity 2: Water Softening Data Table (2 points) Complete the information below based on Data Table 3: Complexometric Titration of Soft Water in the Investigation Manual with the measured and calculated values for each Soft Water Trial. Soft Water Sample Soft Water Trial 1 Soft Water Trial 2 Soft Water Trial 3 Initial EDTA Syringe Reading (mL) 0.000.000.00 Final EDTA Syringe Reading (mL) 0.000.000.00 Volume of EDTA Consumed (mL) (initial – final reading) 0.000.000.00 Moles of CaCO3 in Sample 0.00 x 100 0.00 x 100 0.00 x 100 Molarity of CaCO3 in Sample (M = mol/L) 0.00 x 100 0.00 x 100 0.00 x 100 Water Hardness ppm CaCO3 (mg/L) 000000000 Average Hardness for 3 Trials 000 Images (1.5 points) A required part of this laboratory experiment is to capture pictures of the experimental process and results. Click on the icon in each of the boxes below to include the required images for this lab. Remember to include a card with your name, the correct date and the section number in each image. Note: Failure to submit these images will result in a grade of zero for this lab. Review the Inserting Images into a Worksheet tutorial for further instructions. End Point Comparison Cup (Preparing “End Point” Sample under Preparation, Step 5) Hard Water + pH 10 + indicator BEFORE titration (Activity 1, Step 5) Hard Water + pH 10 + indicator AFTER titration (Activity 1, Step 11) (2.5 points) Post-Lab Questions 1. Most municipal water departments consider water with less than 60 ppm CaCO3 to be soft, 60-120 ppm is moderately hard, 120-180 ppm is referred to as hard water and above 180 ppm is very hard. Classify your Tap Water samples based on your average Tap Water hardness. Average ppm = Click or tap here to enter ppm. Classification = Click or tap here to enter text. 2. Many water softeners are based on ion exchange columns. Indicate whether or not your data supports this use. (Consider the amount of EDTA used and the calculated ppm in the appropriate data tables.) Click or tap here to enter text. 3. In both the Hawaiian Islands and the Virgin Islands, the roofs are designed to collect rain water for use in washing. Is the water collected hard or soft? Explain. Click or tap here to enter text. 4. What are the two main ions that are the cause of water “hardness”. Click or tap here to enter text. 5. Explain why “hard” water reduces the effectiveness of soap. Click or tap here to enter text.