Water Hardness Titration Essay

After added, pick up the beaker and swirl it around lightly for a short period of time.

20) If the solid is still not dissolved, add a tiny amount of hexane and swirl again.

mL cylinder to the beaker on the stir plate and empty it into the beaker. Place the pH probe in the beaker and record the pH in the data table. Drag the beaker to the red disposal bucket. Double-click the bottle of NaHCO3 to move it to the Stockroom counter. Repeat steps 5 and 6 for KNO3.

But the result met the expectation because the color of the solution was reached the end point by changing from red to blue. The primary errors may occur because of misreading the buret while measuring the volume of EDTA. Another error can affect the result of the experiment was that letting the volume of EDTA excess the ending point; so that the volume of EDTA was overapply that lead error. The last source of error was that our unknown sample had high percentage in mass of Mg2+, so that we need more than 50 ml of EDTA( which was the capability of the buret) to reach the end point. We had to refill the buret while measuring; and also the large volume of solution made the color harder to recognize the end point. That also led to error.

After the 5-minute period, take the Elodea and thermometer out of the beaker, pour the mixture into the beaker down the drain and rinse.

Fill a test tube about 1/3 full with cold tap water for use in step 34.

4.Measure 35mL of warm water and add them into each of the 4 test tubes at about roughly the same time. It is essential that the water is warm. Do not seal the test tube.

XII. Take the 250 ml beaker to your lab bench. Set up a gravity filtration with a plastic funnel, folded wet filter paper, and an Erlenmeyer flask. Pour the content in the 250 ml beaker slowly through the filter paper. Wash the filter paper with deionized water. Dispose of the filtrate in the proper labeled waste container.

1) Separate the solid from the liquid in the beaker by decanting the liquid. Ask your instructor to demonstrate the correct procedure.

1 ml of water should be added to the first test tube and make a note. In the second test tube, 1 ml of methyl alcohol should be added. In the third test tube, 1 ml of hexane must be added. Lastly, the fourth test tube will be a control.

Add the sodium hydroxide drop by drop until the end of the point is reached. The sodium hydroxide should be added while maintaining a gentle swirling motion of the flask. The solution should be a very light shade of pink when the titration is finished. Record the final burette reading. Repeat the titration three more

Submerge the graduated cylinder in the plastic tub so that it is completely filled with water. Hold the open end of the graduated cylinder and move it vertically upside-down where the open end of the graduated cylinder is still submerged in the plastic tub. Clamp the graduated cylinder the ring stand of the lab table to keep it in place. perforate a hole in the top of the rubber cork for the solution container. Cut a straw the length of about four inches. place the straw inside of the rubber cork hole. Set up your timer for two minutes.

The 3 remaining beakers were blown into through a straw for 2 min and step 5 was repeated for each of the beakers.

Step 1 and 2 was repeated by using distilled water by replacing the test solution.

For this experiment, the test of hardness of water is crucial and the water hardness refers the existence and amount of the dissolved divalent cations Ca2+ and Mg2+ (some other polyvalent cations included) in the chemical properties of water. (Thompson 2014) The reason that the hardness of water is quite important is because the hardness of water is the determination and the measurement of the quality of water and high-quality water is critical for human and even for other living species as necessary living source. In order to measure the hardness of water, several methods to measure the divalent cation concentration should be used, which are TDS, EDTA and AA (Atomic Absorption Spectrophotometry). EDTA and AA can measure the value of the hardness and TDS is about observation without specific value. Thus, EDTA and AA will be used for the measurement of the concentration of divalent cations in water samples.