Answer:
The coefficient of aluminum nitrate is 2.
Step-by-step explanation:
The reaction between aluminum nitrate and calcium phosphite is:
Al(NO₃)₃ + CaHPO₃ → Al₂(HPO₃)₃ + Ca(NO₃)₂
Now, we need to balance the equation. Let's begin with phosphite anion. On the reactant side we have 1 molecule of the anion, and on the products side we have 3 of it, so we need to add a coefficient of 3 before CaHPO₃:
Al(NO₃)₃ + 3CaHPO₃ → Al₂(HPO₃)₃ + Ca(NO₃)₂
The number of Ca atoms on the reactants side is now 3 and on the products side is 1, so we need to add a coefficient of 3 as follows:
Al(NO₃)₃ + 3CaHPO₃ → Al₂(HPO₃)₃ + 3Ca(NO₃)₂
The reactants side has 1 atom of Al, and the products side has 2. Let's add a coefficient of 2 on the reactant side:
2Al(NO₃)₃ + 3CaHPO₃ → Al₂(HPO₃)₃ + 3Ca(NO₃)₂
Finally, the nitrate anion has 6 molecules on the reactant side, which is equal to the number of molecules of NO₃⁻ on the product side.
Hence, in the balanced equation, we have a coefficient of 2 in aluminum nitrate.
I hope it helps you!