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
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:
Also it would mean that the solution inside it would reach the exact temperature or close to it and not. increase or decrease once the water inside it has reached equilibration. The equilibration It was also very difficult for me to observe exactly when the
The hypothesis for this experiment was, If three different types of waters (saltwater, fresh water, tap water) are tested, then the liquids won’t evaporate at the same rate and tap water will evaporate at the fastest rate because it won’t have any non-volatile substances to hold it back from evaporating.
ash was boiled for 5 minute with 25ml distilled water by covering the crucible with a watch-glass on water bath then cooled. The watch-glass was rinsed with 5 ml of distilled water and this liquid was added in to the crucible. The % of remaining content was deducted from initial % of ash taken (i.e. 100%) to determine the water soluble ash value.
Have you ever stopped and thought, “ what would i do if my kid had a disability?” Or ever question why you act a certain way or if you 're strong enough? In the Articles “Notes From a Dragon mom, What we hunger For and the speech “ This is Water” These authors all share there thoughts on what makes a person act the way they do.
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.
Freezing is a big part of this experiment. When liquids freeze it becomes ice, the molecules begin to form a crystal lattice, which pushes them apart. However, when a liquid is frozen it has taken up to 9% more room than it did when it was a liquid. Another word for freezing is solidifying. But, the purity of a compound can influence at when the liquid to solid change takes place. Most substances freeze at the exact same temperature that they melt. But did you know that hot water freezes faster than cold water? As the water warms up it becomes less dense, the hydrogen bonds stretch and the molecules move farther apart when these hydrogen bonds stretch they allow the covalent bonds to shrink and release their energy. This is equivalent to cooling. So, hot
Each dissociated ion can now act as a charge carrier, allowing the solution to conduct electricity. Substances that produce ions in solution are called electrolytes and the strength of the electrolyte depends on how well it can break apart into ions when dissolved in a solvent. Soluble ionic salts are labelled as strong electrolytes as they are able to completely dissociate from each other.
Water has a great number of roles in living organisms, this is largely to do with the structure and covalent bonding in a single water molecule, and between water molecules. Around 75% of the earth is covered in water, and it is reffered to as the most important Biochemical. Its chemical symbol is: H2O In a water molecule there are two bonding pairs and two non-bonding pairs of electrons. These four pairs of electrons repel one another, forming a tetrahedral pattern.
I thought my brain was in serious illness as cancer because of the excruciating headache. This constant pain had been a couple of month’s since delivering my baby. The result of a MRI shocked me that I was having an earthquake in my brain. A doctor prescribed “lots of fluids” with the diagnosis of dehydration. I told the doctor, “Are you kidding? I spent 500 dollars to see what is wrong with me. Just need to drink water for my headaches?” Of course, I was glad to be diagnosed with no disease or illnesses, but the extravagance—without the insurance—made me regret my decision to go there. However, the knowledge about the importance of hydration affected my life to drink four bottles of water a day. Most of us know we cannot survive without water,
Each water molecule consists of one oxygen atom and two hydrogen atoms. The oxygen atom (or the apex of the water molecule) bears a slight electronegative charge while hydrogen possesses a more positive one. Because opposite charges attract, the water molecules are drawn together. When an oxygen atom is linked to a neighboring molecule's hydrogen atom, a bond called a hydrogen bond is formed. In an ice crystal the hydrogen bonds to give the shape of the crystal so that the grid of molecules surrounds relatively to large spaces. In a liquid form, water has no such spaces; so ice is less dense and will float on liquid water. If not for this, great bodies of water would freeze from the bottom up without the insulation of a top layer of ice and all life in the water would die.
The first step is a quasi-chemical reaction for the formation of a stoichiometric basic hydrate and the second step is the physical adsorption for filling the empty linked cavities by gas molecules by applying Langmuir adsorption theory, resulting into the non-stoichiometric property of hydrate.
= == In my investigation to find out how salt solution concentration affect the mass of potatoes, I will investigate how much the mass of a potato changes if I leave it in a beaker of water with a specified salt concentration for half an hour. I will change the salt concentration after each experiment. Background Knowledge --------------------
of Copper Sulphate. To do this I plan to work out the amount of water
The purpose of this experiment is to use our knowledge from previous experiments to determine the exact concentration of a 0.1M sodium hydroxide solution by titration (Lab Guide pg.141).