Answer:
2HNO3 + Ca(OH)2 ===> Ca(NO3)2 + 2H2O
Explanation:
This a neutralisation reaction. The first thing to note is that this type of reaction forms salt and water.
Note that the formula of water is H2O. So write this at the right hand side.
==> H2O
Next note that the salt should contain the acid radical (NO3) and the metallic part of the base (Ca) written well following the rule for writing chemical equation; thus
==> Ca(NO3)2 + H2O
The next step is to write the reactants at the right hand side of the equation;
HNO3 + Ca(OH)2 ==> Ca(NO3)2 + H2O
The final step is to count the number of atoms in each side of the equation to make sure they are equal and balanced.
In the above equation, H atoms are three at the left hand side add 2 to to H- containig compound on both side as to balance up. Thus
2HNO3 + Ca(OH)2 ===> Ca(NO3)2 + 2H2O
The equation 2HNO3 + Ca(OH)2 ===> Ca(NO3)2 + 2H2O is balance.