An Experiment to Determine the Total Hardness of 4 Different Types of Bottled Water

Seventy percent of the human body is comprised of water. This makes drinking water quality vital. The EPA estimates the average adult consumes 1.2 liters daily or 115 gallons of community (tap) water daily while the average consumption of bottled water per capita in the U.S. is in excess of 30.8 gallons per year and is expected to continue to increase according to the International Bottled Water Association (IBWA) and the Beverage Marketing Association’s 2013 report. Bottled water costs anywhere from 240 to 10,000 times more per gallon than the average cost of tap, but people’s perception that bottled water is purer, safer or healthier is driven, in part, by strong bottled water marketing campaigns that focus on news reports about crises that involve municipal water supplies. (NRDC, “Bottled Water Pure Drink or Pure Hype”) The sources for both tap and bottled waters as well as additives to either enrich or neutralize contents of water determine the mineral and chemical composition of drinking water. Is bottled water really any purer or healthier than local tap water?

The purpose of this experiment is using Compleximetric titration and EDTA to determine the concentration of Mg2+ in solution; and also calculating the percent by mass of MgO in the unknown sample. This procedure results no significant deviations.

The results for the “Total Hardness” test varied between 20 ppm -128 ppm. The “Total Alkalinity” results varied between 28 ppm – 84 ppm. The results for the “Iron” test were between 0 ppm – 1 ppm. For the “Chloride” the results were as low as 20 ppm and went all the way to 8,000 ppm, but for most part the results were from 20 ppm – 60 ppm. The “Color in Water Low Range” test showed that the max APHA Color was 20 and the lowest APHA Color was 0, which is a great result. Results for the “Turbidity Column” test were Not Applicable (N/A). For both the “Chromate” and “Copper” test the results were 0 ppm. The results for “Zinc” varied between 0 ppm – 2

The goal of this experiment was to determine the empirical formula for a hydrate of magnesium sulfate and water. The technique that was used was measure the mass of the hydrate and then apply heat to evaporate the water. Then determine the mass of water that was in the hydrate and the mass of the remaining magnesium sulfate. The equation for the hydrate is determined by calculating the mole to mole ratio of the water and the anhydrous. The resulting formula will be formated as: MgSO4*_H2O

In Rosemary Jolly's class, students performed the hot plate procedure in order to evaporate the water from the unknown hydrate.  The equipment that the students used were two 100-mL beakers, an analytical balance, a hot plate, and a clean glass rod to stir the substance.  Students obtained about 1 or 2 g of the unknown hydrate into one of their 100-mL beakers.  They determined the combined mass of the sample and the beaker.  After doing this, they placed the beaker onto a hot plate that was on a medium setting.  Using the glass rod, students stirred their beakers in order for all of the unknown hydrate to melt until a dry powder appeared.  Once the dry powder appeared in the beakers, the students took their beakers off of the hot plate in order to cool to room temperature.  They placed the beakers on an analytical balance to record the mass of the beaker and residue.  This information was used later in the experiment to find the number of moles of water per formula weight unit of magnesium sulfate.  Students repeated the procedure with their second 100-mL beaker.  Once the second trial was completed, they used their data to determine the average number of moles of water present in the magnesium sulfate

These different mistakes during the lab caused the results to change during the

As with many experiments that are performed in a setting where we cannot be exact on every measurement, error could arise from it. For instance, from this particular experiment, we needed to measure 5mL of water and 5mL of the borax mixture after it had cooled. Measuring 5mL with the bulb pipet that we were provided was not an exact measurement tool. The pipets provided were not calibrated and/or could have contained pockets of air with the assumed 5mL of water or solution.

The controversy of bottled water verse tap water can be argued on both sides. However, tap water is the better alternative in the long run. Some may say there is a distinct taste difference between the two, yet most can't tell. In a college classroom, a group of students completed an experiment where they tasted a variety of waters: Great Value, Zephyrhills, and tap water. Most students guessed incorrectly, not tasting a difference (Combass). Although people have concerns with tap water, it is the most convenient. Not only is tap water cheaper, it is the safest source that positively impacts our environment.

The overall point of the lab was finding the concentrations by using a variety of formulas and even a graph that really pulled it all together. It doesn’t seem as if the proceedure leaves any room for errors, since it could be performed flawlessly if all the measurements are correct. Overall, finding the concentration of solutions and learning how to use and make a claibration curve was productive and

The third error encountered during testing also occurred during the first experiment. After the first three days of the trial, since the beakers were not covered, the water level began to decrease. Since more and more water was evaporating, the salt concentration became higher and higher causing the results to be completely inaccurate. In order to avoid this, the beakers could have been covered whilst not being used to ensure that minimal evaporation

Speedwell Forge Lake. It had a Ca concentration of 4.8 mg/L, Mg concentration of 1.3

In Figure 1, the image is a basic table of our results it contains the pH levels and what we received for the rate of absorption. In Figure 2, the chart shows the number received, and the possible error for each point. This illustrates the issue of the data being all over the place.

On an average Americans spend about $13billon per year on water bottles and consume about 34 gallons of a bottle of water, According to Thompson, Manroe, & Vaughan (2017) Many Americans purchase a bottle of water because it is more convenient for them. A lot of American believes that bottle of water is much healthier than tap water, they believe that bottle of water contains more nutrients, however, that is not true; According to International Bottled Water Association (2014) “bottle of water has no other nutritional advantages over tap water”. Many Americans also believe that bottled water is much safer and healthier than tap water. However, there is no scientific evidence that supports this claim. Although, I am aware there is no evidence

This error could have been affected by the spill that occurred. Otherwise, the techniques that were present in this lab were sufficient. The only improvement that could be made with this lab is an emphasis on consistency and better monitoring of lab contents as to avoid spills such as the one that occurred in this

There are some silly mistakes that could have occurred in this lab that I performed. One common