Question
Question: \(CaC{O_3}\xrightarrow{{heat}}CaO + C{O_2}\) From the above equation calculate the amount of carbo...
CaCO3heatCaO+CO2
From the above equation calculate the amount of carbon dioxide in grams liberated by heating 25g of calcium carbonate.
Solution
In a chemical reaction, when one mole of reactant produces one mole of product that means first reactant atomic mass will produce atomic mass of product. So we should know the exact stoichiometric coefficient of chemical reaction of every reactant and product.
Complete step by step solution:
We need a stoichiometric reaction that represents the given change
Here the calcium carbonate decomposes to give calcium oxide and carbon dioxide.
The reaction of decomposition of calcium carbonate can be represented as –
CaCO3(s)heatCaO(s)+CO2(g)↑
Calcium carbonate calcium oxide carbon dioxide
Here in this case the stoichiometric coefficients are 1 only. We can say 1 mole of calcium carbonate gives 1 mole of carbon dioxide.
But given mass is 25g of calcium carbonate,
Now, number of moles =molarmassgivenmass
Molar mass of calcium carbonate ( CaCO3 ) = molar mass of calcium + molar mass of carbon + 3(molar mass of oxygen
Molar mass of calcium carbonate = 40 +12 + 3(16) = 100gmol−1
For 25gof calcium carbonate, number of moles =100gmol−125g=0.25mol
According to the stoichiometry of reaction, 0.25mol of calcium carbonate will give 0.25mol of carbon dioxide.
Molar mass of carbon dioxide = molar mass of carbon +2(molar mass of oxygen)
Molar mass of carbon dioxide = 12 + 2(16) = 44gmol−1
Now 1mole of carbon dioxide contains 44g of carbon dioxide.
Therefore, 0.25mol of carbon dioxide =0.25mol×44gmol−1=11g of carbon dioxide.
**Hence, 25g of calcium carbonate will produce 11g of carbon dioxide on decomposition.
Note: **
Similarly we can calculate the amount of calcium oxide produced. Since 0.25mol of calcium carbonate is getting decomposed then 0.25mol of calcium oxide will produce. And 0.25mol of calcium oxide contains =56gmol−1×0.025mol=14g of calcium.