Lakes that have been acidified by acid rain (HNO3 and H2SO4) can be neutralized by a process called liming, in which limestone (CaCO3) is added to the acidified water. Write ionic and net ionic equations to show how limestone reacts with HNO3 and H2SO4 to neutralize them. How would you be able to tell if the neutralization process was working?
Solution 104P :
Let’s consider Nitric acid (HNO3) and limestone (Calcium carbonate (CaCO3) ):
The balanced molecular equation is :
2 HNO3(aq) + CaCO3(s) → Ca(NO3)2(s) + CO2(gas) + H2O(l)
The complete ionic equation :
H+(aq) + NO3-(aq) + CaCO3 (s) → Ca2+(aq) + NO3-(aq) + CO2(gas) + H2O(l)
The net ionic equation :
To write net ionic equation, we cancel out the ions that is on both the sides, which are spectator ions.
And the net ionic equation is as follows :
H+(aq) + CaCO3 (s) → Ca2+(aq) + CO2(gas) + H2O(l)
In the above reactions, we can say that by adding limestone, the nitric acid neutralized to form calcium nitrate and precipitated and water was formed and CO2 was liberated.