Balance the equation ca0 + hno3 arrow ca(n03)2 + h20

Explanation:

You don't normally do this, but you might start by balancing the complex ion which is NO3^-

There are 2 of these on the right side of the arrow so make two on the left.

CaO + 2HNO3 arrow Ca(NO3)2 + H2O

That looks balanced. Let's check it out.

Species             Ca             H              NO3            O

Left                     1                2               2                 1     on the CaO

Right                   1                2               2                 1    on the H2O

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.