Hydrates and their thermal decompositions how does it work?
98002
Think about what hydrates are... hydrated chemicals... an example:  CoCl2 * 6H2O.   if you heat water up, what happens?  It evaporates leaving just CoCl2.  You have "Freed the hydrate", having left the "Anhydrous" form of the complex.
146503
chemical reaction\n-------------------\nBaking soda added to water raises the temperature slightly. Chemical reactions are either endothermic or exothermic. Endothermic means you have to put energy (heat) in to make the reaction go while exothermic means there's energy (heat) left over. Left over heat will raise the temperature. Baking soda and water is exothermic and so the water gets a little warmer. This is because the binding energy of the chemical bonds of the products has an excess over the binding energy of the components. Therefore, energy is released and the water warms up.\n\nEndothermic reactions do not usually go off at room temperature without heating. Baking soda is NaHCO3 and water is H2O. Added together you get NaOH and H2CO3 which are sodium hydroxide and carbonic acid. Carbonic acid is the fizz in soda. Eventually the mixture releases CO2 gas when the H2CO3 breaks down into H2O and CO2. The solution of H2O and CO2, if left alone uncorked, will lose its fizz. The water CO2 mixture will cool off slightly when the fizz (CO2) is released because the CO2 takes some energy with it. As the water evaporates it cools off because the warm molecules of water evaporate first! That's right! The warm ones!\n\nWhen we say temperature we really mean the average temperature of the molecules in a glass of water. Some are colder than average, some are warmer and many are close to the average. Evaporation requires energy, called the latent heat of vaporization. This heat comes from the warm water molecules. When the water evaporates it cools the glass off. That's why sweating makes you cool off too.\n\nA reaction that is endothermic will take place at a much slower rate because there are always some warmer molecules in the mixture. When we warm up the chemicals we raise the average temperature and a lot of the molecules can then react. When you mix bread dough the mix usually gets noticeably warmer after you put in all the ingredients. This is probably safe to try out at home with some adult help. Just ask your folks to help you whip up a batch of "soda bread." You can eat the result!
1165181
It's been awhile since i've done this but i'll give it my best\n\nFirst off, the first energy you need to calculate is the energy needed to raise the temperature of ice to 0 degrees C. so...\n\n(12.37 g)(.48 cal/deg/g)(35 deg) = +207.816 cal\n\nWhen the ice changes to water you have a positive heat of fusion. So...\n\n(12.37 g)(80 cal/g) = 989.6 cal\n\nNext you have to raise the water temperature from 0 degrees C to 100 degrees C. So...\n\n(12.37 g)(1.0 cal/deg/g)(100 deg) = 1237 cal\n\nNext you have the positive heat of vaporization.\n\n(12.37 g)(540 cal/g) = 6679.9 cal\n\nNext once it is steam, you must raise the temperature from 100 degrees C to 146 degrees C. So...\n\n(12.37g)(.48 cal/deg/g)(46 deg) = 273.1296 cal.\n\nNow that you have the energy for each step add them together.\n\n207.816 + 989.6 + 1237 + 6679.9 + 273.1296 = 9387.45 cal\n\nI'm pretty confident in my breakdown but it defintely wouldn't hurt to have someone else check it
115198
There are several.\n\nA few\n\n1) Copper sulphate penta hydrate (Cu SO4. 5 H2O)\n2) Ferrous sulphate hepta hydrate (Fe SO4. 7 H2O)\n3) Potash Alum (K2SO4. Al2 (SO4)3. 24 H2O)\n\nThe first two can exist in different states of hydration. The former as mono and tri hydrates also and the latter as mono, tetra and penta hydrates also.
248591
CaO + H2O => Ca(OH)2\n\ncalcium oxide + water => calcium hydroxide\n\nThis is a great site for this - the reaction between CaO and water is an exothermic reaction (1)\n\nthe second reference is even better - not simply a diagram but a torn apart "self-heating" can\n\ngood luck!\n\nSomething else you might want to looking - MRE's (meals ready to eat)
263822
I've used it as a process in which a compound is dissolved in their recrystalization solvent (found in the Merck index) then filtered. The new filtered solution is allowed to cool and the compounds recrystallize creating more pure crystals. \nLook up types of organic purifications.
186407
One way to tell is to look up the heats of formation for the reactants and products.  Add all the reactants up and all the products up.  Subtract the reactants from the products.  If the answer is negative, the reaction is exothermic.  \n\nThe other way is to actually carry out the reaction and see if it liberates heat or not.
182902
Specifically, water binds to the mixture, and blocks free oxygen from reaching the material to be oxidized-its a simple smothering reaction, and is why water is effective for putting out fires.  Salt is also effective, but is reduced by the relatively large size of the particles which allows some oxygen in.  There is no specific inhibition of the oxidization reaction other than this-water is neutral to this reaction, except as a space inhibitor.
22608
Hi Asterion, All icy surfaces in fact contain small puddles of water. Because salt is soluble in water, salt applied to such surfaces dissolves. Liquid water has what is known as a high dielectric constant, which allows the ions in the salt (positively charged sodium and negatively charged chlorine) to separate. These ions, in turn, react with water molecules and hydrate—that is, form hydrated ions (charged ions joined to water molecules). This process gives off heat, because hydrates are more stable than the individual ions. That energy then melts microscopic parts of the ice surface. Thus a substantial amount of salt spread over a large surface can actually thaw the ice. In addition, if you drive over the ice in your automobile, the pressure helps force the salt into the ice and more of this hydration occurs.
38024
go to howstuffworks.com search for hydralics they've got a great article on them
838918
Its a decomposition equation. In essence Sodium Chloride (salt) breaks down into the Sodium ion and the Chlorine Ion. Chances are it's talking about NaCl when it's an aqueous solution (a solution who's solvent is water)
277199
CuSO4 . 5H20 -> CuSO4 + 5H2O\n\nIt is just a hydrate so basically you are just getting water out of the salt. Copper(II) sulfate pentahydrate is blue while CuSO4 is a white salt.
536437
In order to overcome the strength of the  oxygen-hydrogen bond of water, a force must be used to electrochemically decompose a sample of water.  This is called a decomposition voltage and it is roughly about 1.2 volts at 25 degrees C.  In the lab a little more voltage is necessary to have the reaction occur at an acceptable rate.\nThis requires a cathode and an anode to produce hydrogen and oxygen gas, and of course a voltage.  \nElectrolysis of water:\n4H+ (aq) +4e- ------ 2H2(g) reduction at cathode\n2H2(l) ------- O2(g) + 4H+(aq) + 4e- oxidation at anode\n\n2H2O(l) ------- 2H2(g) + O2(g) net reaction\n\nEnergy: DeltaGrxn = +474.4 KJ\n\nGood night and Good Luck.
782187
When salt (NaCl) is absorbed into water (H2O) A new molecule is formed (NaH2ClO). When this new molecule is frozen, the crystalline structure is much stronger than that of regular water. This is why icebergs sink ships and ice cubes can be crushed by your refrigerator.
281476
Hi Krish_darwin, here is my answer to your problem ;)-\n\nFirst of all, we have to define what we mean by the thermal stability of a hydroxide, the thermal stability refers to that property of a hydroxide due to which, it resists its breakdown into its oxide and hydrogen i.e.\n\nMOH + Heat --------> M2O + H2\n\nAs we know that, in the 1st gp, as we move up, oxides are more stable because, the polarising power of the cation increases up the group.\n\nSo, that means that, as we move up, hydroxides become less stable and oxides become more stable. (see reaction)\n\nTherefore, we can say that thermal stability increases down the group.\n\nNow, coming to stability, as we know, lattice enthalpy decreases down the group, obviously, the stabilty of the hydroxide decreases down the group. Thus, this reaction can take place more easily down the group-\nMOH --------> M+     +     OH-
372993
If you mean the decomposition of a chemical (electrolyte) by the passage of an electric current, you just get two electrodes (pieces of metal) that won't be attacked by the chemical or its electrolysis products and stick them in the electrolyte, and then connect the electrodes to a source of electrical current. You have to experiment with the voltage to be sure it is enough to produce electrolysis at a reasonable rate. If you want to collect any gaseous products of electrolysis, you can let the gas bubble up into an inverted container that is initally filled with the electrolyte. \nElectroplating (ref.) is a related phenomenon. In this case one electrode, connected to a negative voltage, is the metal item you want to receive the plating and the other, connected to a positive voltage, is the metal that provides the plating. The electrolyte is a water solution of a salt of the plating metal.
808639
The answer given earlier is more feasible i.e decomposing sodium hydrogen carbonate, the equation thus:\n\n2NaHCO3 --> Na2CO3 + CO2 + H2O\n\nBut, the decomposition for your specific enquiry thus:\nNa2CO3 --> CO2+Na2O\n\nI hope this helps