I learnt this one in school at the age of 11 years.
CaCO3(s) ===heat===> CaO(s) + CO2(g)
Is the thermal decomposition of calcium carbonate.
You need to heat the Calcium carbonate to 'red' heat (1000 oC). where upon CO2 is liberated.
In an experiment you can not see any change in calcium carbonate (CacO3) is white in colour as is Calcium Oxide (CaO). The two ways to check for the liberation of CO2 is :-
When cooled the residue solid(CaO) should weigh less, then before the experiment. or
Collect the liberated CO2 and bubble through lime water; it turns 'milky' in colour.
while searching for the exact mechanism for the decomposition i came across several of the actual reactions themselves.
credit to:
Dan Berger Bluffton College http://cs.bluffton.edu/~berger
Hmmm... let's see if we can analyze your question, Ben. The reaction you performed is the following, considered as two coupled equilibria:
Carbonic acid is a weak acid in aqueous solution, which means that it is only partly dissociated:
The equilibrium constant for this reaction is about 10-5. So really very little of the hydrogen in the carbonic acid is actually in the form of hyronium ions; dissolved in vinegar (pH about 2.4), only 0.4% of the carbonic acid will be dissociated. First, as long as the dissociation of carbonic acid is reversible, the extent to which it is dissociated in water is irrelevent and we can treat all carbonic acid (not CO2, that's another matter) as H2CO3. Second, the decomposition of carbonic acid is a rapid equilibrium at room temperature:
The equilibrium constant for this reaction is about 32, which means that only about 3% of dissolved carbon dioxide will be in the form of carbonic acid. The amount of CO2 which remains in solution depends on its solubility:
Since the solubility of CO2 is only 1.45 g/L (about 0.03 mol/L) at 25° C, most of the carbonic acid formed by dissolving an eggshell in vinegar will escape into the atmosphere. Ultimately, this drives the process of dissolving the eggshell by removing carbonic acid as it is formed! I hope this answered your question; if not, feel free to contact me directly.
--i had been searching for the e- transfer via curved arrow, but i guess i could wait one hour to find out (class in a few)---Erich
An example of a decomposition reaction for Calcium Carbonate isCaCO3 → CaO + CO2
Where the calcium carbonate derives into its original state.
The equation for the decomposition of carbonic acid is: H2CO3 -> H2O + CO2. The equation for the decomposition of sulfurous acid is: H2SO3 -> H2O + SO2.
H2Co3--> CO2(g) + H2O(aq)
The equation for the decomposition of H2SO3 is: 2H2SO3 -> H2O + SO2 + S.
The word equation for the formation of carbonic acid is "carbon dioxide + water = carbonic acid".
The reaction between magnesium carbonate and nitric acid involves both a double displacement reaction, where magnesium carbonate and nitric acid switch partners to form magnesium nitrate and carbonic acid, and a decomposition reaction, where carbonic acid breaks down into water and carbon dioxide.
This equation is Ca + H2CO3 => CaCO3 + H2.
Dihydrogen Sulfur Trioxide or sulfurous acid
The equation for the decomposition of H2SO3 is: 2H2SO3 -> H2O + SO2 + S.
The word equation for the formation of carbonic acid is "carbon dioxide + water = carbonic acid".
It forms Carbonic Acid and this is a decomposition reaction
The reaction between magnesium carbonate and nitric acid involves both a double displacement reaction, where magnesium carbonate and nitric acid switch partners to form magnesium nitrate and carbonic acid, and a decomposition reaction, where carbonic acid breaks down into water and carbon dioxide.
This equation is Ca + H2CO3 => CaCO3 + H2.
H2CO3 is Carbonic Acid or HCO3- is Bicarbonate
Carbonic acid comes from the reaction of carbon dioxide with water or with water vapor in the air. Here's the equation: CO2 + H2O => H2CO3
Dihydrogen Sulfur Trioxide or sulfurous acid
The litmus test can help determine if sulfurous acid is an acid or a base. If sulfurous acid turns blue litmus paper red, it indicates that it is an acid. This test does not provide direct information about the stability of sulfurous acid.
H2CO3---------- 2 H+ + (CO3)2-
When carbonic acid decomposes we get carbon dioxide and water. Other substances may be present too, depending on which raising agent is used to produce the carbonic acid.