The purpose of the lab is to determine the effectiveness of using gravimetric analysis in determining the hardness of a water sample. More specifically, this lab tests for the amount of dissolved substances such as magnesium carbonate and calcium carbonate. The amount of these substances dissolved in water determines water hardness as they contribute cations to water which result in a buildup of scum or solid CaCO3 as a precipitate. All water tends to have a different hardness as it is determined by the geography area of the water as different regions contain different substances that can dissolve into water. Table 1: Classification of Water Hardness (Flinn Scientific, Inc)
Classification mg/L grains/gal
Soft 0-17.1 0-1
Slightly hard 17.1-60 1-3.5
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The amount of the calcium carbonate will be determined by the amount of precipitate created in the reaction. The objective of this lab is to separate a molecule or an ion from its compound in a precise fashion. Gravimetric analysis is a precise method when it is done correctly. The accuracy of gravimetric analysis for determining water hardness will be assessed by calculating the percent yield as predicted by the balanced chemical …show more content…
Hard water can cause health problems and can be costly as it can create scum buildups that interfere with the movement of water through pipes. Gravimetric analysis, a technique that uses the mass of a precipitate to determine the composition and identity of an unknown compound, was used to determine the water hardness and the effectiveness of this technique was analyzed. By examining the data it can be concluded that gravimetric analysis can be effective in measuring water hardness. However, there was a correlation between the percent yield and the initial theoretical water hardness. This can be explained by looking at the reaction at the particulate level. As the concentration of ions increases, the likelihood they will interact also increases and therefore solutions with higher concentrations are more likely to have a higher percent yield than solution that are more dilute. Errors that may have affected percent yield in the gravimetric analysis could have been losing substance while transferring or not stirring the compound long enough so that all the ions could interact and form a precipitate. Based on the results, gravimetric analysis is an effective method of determining water hardness if the theoretical sample is a concentrated
Two solutions were prepared by using Calcium Nitrate Ca(〖NO_3)〗_2 with concentration of 0.101 M, Potassium Iodate KIO_3 with concentration of 0.100 M, and deionized water. First solution contained 25.0 mL of Calcium Nitrate and 25.0 mL of Potassium Iodate. In the second solution, 15.0 mL of deionized water were added with 10.0 mL Calcium Nitrate and 25.0 mL of Potassium Iodate. Each of these solutions was mixed for 15 minutes. After the reaction of the solutions took place, each of the solutions was filtered. To remove water liquid from the filtered solution, both of the precipitates in the
At this point the identity of the unknown compound was hypothesized to be calcium nitrate. In order to test this hypothesis, both the unknown compound and known compound were reacted with five different compounds and the results of those reactions were compared. It was important to compare the known and unknown compounds quantitatively as well to ensure that they were indeed the same compound. This was accomplished by reacting them both with a third compound which would produce an insoluble salt that could be filte...
I did accomplish the purpose of the lab. First, I determined the percentage of water in alum hydrate, and the percentage of water in an unknown hydrate. The results are reasonable because they are close to the example results. Second, I calculated the water of crystallization of an unknown hydrate. Furthermore, I developed the laboratory skills for analyzing a hydrate.
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
Its value is usually around the 1.00. Thus, as urine becomes more concentrated, specific gravity will become higher. Specific gravity was expected to gradually decrease as urine becomes diluted and less water is reabsorbed. The value was not expected to change much, staying somewhere around the value of 1.00 for each subject. The results were in accordance with the hypothesis as all subjects specific gravity had slightly decreased over the 90-minute time period, staying within close proximity of 1.00. The subjects with the greatest change were the ones drinking 16 ml/Kg of water as urine seemed to be diluted most in this group. The graph shows that specific gravity of subjects drinking caffeine free soda had an initial increase then decreases at the end. Each group drinking varying amounts of water had the lowest average of specific gravity showing that dilution of urine can affect the value of specific
This paper discusses how cosmology and how philosophy can be connected to one another. In order to explain this reason, the paper is broken down into three subtitles which are: metaphysics, religion, and ontology. Each part connects to cosmology in one term or another. In each subtopic, it will discuss the topic, its background in the philosophical review. As a result, in the conclusion, it will discuss how cosmology compares to them all.
A cuvette was filled 3/ 4ths of the way and the absorbance measured in a spectrophotometer. The data was compiled as a class and recorded. The Spectrophotometer was blanked using a test tube of distilled water.
This would give us an extra measure of accuracy each time. Another way to improve the experiment and to produce consistent readings was to used distilled water. This is because the distilled water contains no impurities and therefore no hardness in water.
The Gravimetric Stoichiometry lab was a two-week lab in which we tested one of the fundamental laws of chemistry; the Law of Conservation of Mass. The law states that in chemical reactions, when you start with a set amount of reactant, the product should theoretically have the same mass. This can be hard sometimes because in certain reactions, gases are released and it’s hard to measure the mass of a gas. Some common gases released in chemical reactions include hydrogen, carbon dioxide, oxygen and water vapor.
The Effects of Gravity There are some people who worry when they're outside, if they don't keep a good grip on the ground, they'll just go flinging off into space. They needn't really worry. about this, because gravity generally keeps that sort of thing from happening. The thing is, no one is really sure what causes gravity, but the effects have been studied by many. physicists and astronomers of the world.
Moisture is heavy, and thus it can change the results of the experiment, as we only want the weight of magnesium and the magnesium oxide.
The amount of hydrochloric acid. 3. The concentration of the hydrochloric acid. 4. The surface area of the calcium carbonate.
Generally pycnometer is made of glass, with a clos-fitting ground glass stopper with capillary tube through it, so that air bubbles mas escape from the apparatus. This device enables a liquid density to be measured through an appropriate working fluid, such as mercury or water, using analytical balance. When the flask weighed empty, full of water, and full of a liquid whose relative density is desired, then relative density can be easily calculated. The specific gravity results show that subsoil specific gravity varies between 2.45 and 2.7. Pycnometer analysis work system shown in Figure 12.
Richardson, S. Water Analysis: Emerging Containments and Current Issues. Journal of Analytical Chemistry. 2003, 75, 2831-2857.
Gravity is the force that pulls two objects together, and the mass of the human body depends on gravity. The more the mass there is, the amount of the gravitational force will increase. The study of the Earth’s gravitational field itself is complex and deeply fascinating. Likewise, studying its relation to the human body makes it even more thought provoking. A gravitational field is simply the area of space neighboring a body that has another body experiencing a gravitational attraction force. As human beings and just general species, our state in Earth is not the same as it is up in the atmosphere or another planet. Unfortunately, the term “gravity” is thrown around futilely these days, but in this essay you will learn its purpose in our Earth, and all the notions that go along with it.