Introduction Hydrates are compounds that form crystals that have water molecules in their structure. Barium chloride dihydrate, or BaCl2●2H2O is an example of this, with five water molecules for every one molecule of barium chloride. The water is called the water of hydration, and the dot between the barium chloride and the water molecules means that the two types of molecules are bonded together. The water of hydration is heated out of the hydrate when the temperature reaches above 100℃, since the hydrate bonds are weaker than the ionic bonds that are formed between the salt ions. The water is driven off, leaving the anhydrous salt behind. BaCl2●2H2O (s) + heat → BaCl2(s) + 2H2O (g)
Is an example of this as the BaCl2●2H2O is the hydrate,
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Results
Data
Trial 1
Trial 2
Formula of salt/anhydrous salt
BaCl2
BaCl2
Mass of empty crucible (g)
8.9555
7.9581
Mass of crucible and hydrate (g)
10.0247
8.9743
Mass of crucible and hydrate (after first heating) (g)
9.8646
8.8223
Mass of crucible and hydrate (after second heating) (g)
9.8646
8.8221
Calculations
Mass of the hydrate (g)
1.0692
1.0162
Mass of anhydrous salt (g)
0.9091
0.8640
Mass of water lost (g)
0.1601
0.1522
Percent water in hydrate
14.97%
14.98%
Molar mass of anhydrous salt (amu)
208.2
208.2
Moles of water lost (mol)
0.008885
0.008446
Moles of anhydrous salt (mol)
0.004366
0.004150
Moles of water per mole of anhydrous salt (mol)
2.035
2.035
Average moles of water per moles of anhydrous salt (mol)
2.035
2.035
Empirical formula
BaCl2●2H2O
BaCl2●2H2O
Sample Calculations NOTE: All data comes from Trial 1
Mass of the hydrate = Mass of crucible and hydrate - Mass of empty
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The number calculated for the moles of water per mole of anhydrous salt were precise, having a PPT of 0 since they were both the same. There was only a 1.75% error between the 2.035 mol of water per mol of anhydrous salt and the whole number of 2 that was needed for the empirical formula. The experiment was conducted both accurately and precisely. The all of the water was removed from the hydrate in the first trial, which can be confirmed by the fact that there was no change on the scale when the crucible was massed after the first heating and after the second heating. No change in mass means that there is no water left in the hydrate that could be removed. In the second trial, however, it is evident that almost all of the water was removed, seeing as there was a small change in the mass of the crucible between the first and the second heating. This difference was minimal, only being 0.0002 g. There are no obvious experimental errors that occurred, however there could have been the error of not heating the crucible long enough to get all the water out of the hydrate. If this had happened, the difference between the mass of the crucible after the first heating and after the second heating would have been more than 0.003
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
In our experiment we utilized the hydrate cobaltous chloride. Hydrates are crystalline compounds in which one or more molecules of water are combined with each unit of a salt. Cobalt (II) chloride hexahydrate is an inorganic compound which is a deep rose color in its hydrated form. As an inducer of
Hydration of alkenes is characterized by the addition of water and an acid-catalyst to a carbon-carbon bond leading to an alcohol. Dehydration is exactly the opposite in which dehydration of an alcohol requires water to be removed from the reactant. Equilibrium is established between the two processes when the rate of the forward reaction equals the rate of the reverse reaction. The alkene that is used in this experiment is norbornene. Through hydration of norbornene, an alcohol group should be present on the final product yielded what is known as exo-norborneol. Percent yield is a numerical indication of how much of the reactant was actually reacted to yield product. The equation for percent yield is shown below:
Then comparing the initial temperature of the water to the temperature after the reaction between various salts has occurred, I was able to determine which salt resulted in an exothermic reaction when combined with water. The NaCl and KNO3 were both endothermic reactions because the final temperature was less than the initial temperature. This means that heat was lost by the surroundings, the solution, and gained by the system, the reaction. MgSO4 was exothermic because its final temperature was greater than its initial temperature, which means that heat was gained by the solution and lost by the reaction. Therefore, MgSO4 was the best salt to use for the heat pack because it was the only salt we tested that released heat. After this, we ran three trials with varying volumes of water in order to find the volume ratio of salt to water that would produce a reaction that could release enough heat to raise the temperature of the solution by about 20°C. From this information, I could find the changes of enthalpy of the reaction, which was able to be a substitute for changes in heat content because the reaction took place at a constant
To begin the experiment, we measured 5cc of water and 5g of NaCl and added them to a test tube. Next, we stoppered the test tube and shook vigorously for two or three minutes. After we observed that the solution was saturated and massed an evaporating dish (18.89g) and poured most of the solution into it, while being careful not to pour any undissolved solid into the dish. Next, we massed the evaporating dish with the solution and found it to be 23.32g. The next step was to slowly evaporate the solution in the evaporating dish using a hot plate. Once the liquid was evaporated from the solution, to the best of our ability, we massed the remaining solid in the dish, which we found to be 20.32g. This was the last step of the physical portion of the experiment, and we proceeded to the calculations. First, we found the mass of the remaining solid by subtracting the mass of the evaporating dish from the mass of the solid and evaporating dish, which we found to be 1.43g. To find the mass of the evaporated water we subtracted the mass of the solid and evaporating dish from the mass of the solution and evaporating dish, which we found to be 3g. Because the density of water is 1g/1cc, the mass is the ...
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 hydrolysis of salts can be determined on the basis of the strength of the acid or base which forms it. If the salt is formed from a strong acid and a strong base, such as NaCl, the salt will form a neutral solution, since the anions of the acid and the cations of the base will not react with the water. A salt from a weak base and a strong acid, with NH4Cl as an example, will form an acidic solution. This is due to the cations from the base that increase the hydrogen ion concentration, by donating protons, which is known as a Bronsted acid. When concerning a salt formed by a weak acid and a strong base, such as Na C2H3O2, a basic solution will form. The anions of a weak acid in water will generate hydroxide ions, since the molecule will accept protons. It is termed as a Bronsted base. Though no examples were present, the salt that forms from a weak acid and a weak base can be determined by comparing the Ka (cation) and the Kb (anion) values. Most metallic ions, those found in groups 1A and 2A on the periodic table, such as Ca2+, a strong base, will have no reaction with water. However, all other metallic ions will undergo hydrolysis to form an acidic solution, such as KAl (SO4)2. As the Al is the molecule that was hydrolyzed, the spectator ions would not be present in the hydrolysis reaction, as is shown in the net ionic equations
Human bones and teeth are known for their strong and dense structures. The major component that is being responsible for this property is a mineral called hydroxyapatite. Hydroxyapatite is a mineral that forms through a controlled process of crystalline solid apatite and other various elements. The importance of proper proportions in this process is very significant: all elements (calcium, phosphorous, oxygen, and other ions) need to be available with an adequate amount. 1
The molar volume of the H2 in our experiment is very close to the theoretical molar volume, but I think that the deviation lies in the temperature of the H2O: in the first trial it is too high and in the second one too low.
When a miscible salt is completely dissolved in liquid solvent to dissociate positive and negative charged ions, then this mixture is called liquid electrolyte.
In this lab 2-methyl-butyn-2-ol is hydrated to 3-hydroxy-3-methyl-2-butanone. This process was preformed by using a strong acid which created an enol, and then the enol tautomerized. Due to this being a terminal alkyne, only one product will be formed. Techniques such as simple distillation, reflux, and gravity filtration were used to produce and separate the product from the mixture that it was in. When performing this lab using only one equivalent of alkyne produced a low percent of 1%. The low yield is a result of using one equivalent instead of two.
Fluid is a major component of our body and serves a vital role in our health and in normal cellular functions by serving as a medium for metabolic reactions in the cell. Fluid also moves nutrients into the body by the digestive system and moves waste products out of the body by way of the kidneys. Extracellular and intracellular fluids contain solutes such as dissolved nutrients, waste products and charged particles called electrolytes. Fluid and electrolytes play a vital role in homeostasis, which is the ability of the body (or cell) to maintain a relatively constant internal environment when dealing with external changes. Homeostasis must exist for the cells to function properly and the maintenance of fluid and electrolyte balances are necessary for homeostasis. To maintain homeostasis, ions move between the extracellular and intracellular fluid compartments through selectively permeable membranes by a variety of methods such as
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of Copper Sulphate. To do this I plan to work out the amount of water