Question

Show your work. Write a balanced net ionic equation for the following reaction. H3PO4(aq) + Ca(OH)2(aq) Ca3(PO4)2(aq) + H2O(l)

Answer 1

Balance Net Ioic Equation: 6H⁺(aq) + 6OH⁻(aq) → 6H₂O(l)

Step-by-step explanation:

First off, it is important to understand that there are two ionic equations.

we have the complete ionic equation and net ionic equation.

The complete ionic equation is used to describe the chemical reaction while also clearly indicating which of the reactants and/or products exist primarily as ions in aqueous solution.

The net ionic equations however is the complete ionic equation after removing the spectator ions. Spectator ions are ions that are present in the reaction mixture but do not participate in it.

To write a net ionic equation:

1. Write the balanced molecular equation.
2. Write the balanced complete ionic equation.
3. Cross out the spectator ions that are present.
4. Write the "leftovers" as the net ionic equation.

Step 1

H3PO4(aq) + Ca(OH)2(aq) → Ca3(PO4)2(aq) + H2O(l)

Upon balancing, we have;

2H₃PO₄(aq) + 3Ca(OH)₂(aq) → Ca₃(PO₄)₂(aq) + 6H₂O(l)

Step 2

To write the complete ionic equation:

- Start with a balanced molecular equation.

2H₃PO₄(aq) + 3Ca(OH)₂(aq) → Ca₃(PO₄)₂(aq) + 6H₂O(l)

- Break all soluble strong electrolytes (compounds with (aq) beside them) into their ions.

- Indicate the correct formula and charge of each ion

indicate the correct number of each ion

write (aq) after each ion

- Bring down all compounds with (s), (l), or (g) unchanged.

6H⁺(aq) + 2PO₄³⁻(aq) + 3Ca²⁺(aq) + 6OH⁻(aq) → 3Ca²⁺(aq) + 2PO₄³⁻(aq) + 6H₂O(l)

Step 3

You can recognize spectator ions by looking for ions that are present on both sides of the equation. They will always have the same exact formula, charge, and physical state. They will also be present in exactly the same number on both sides of the equation.

The spectator ions in this case are; PO₄³⁻(aq) and Ca²⁺(aq).

Step 4

6H⁺(aq) + 6OH⁻(aq) → 6H₂O(l)

Answer 2

To do a balancing to result to a balanced equation, we do elemental balance from each side of the equation. Hence we do separate balances for H, P, O and Ca. In this case, the final balanced equation after balancing elementally is 3 Ca(OH)2(aq) + 2 H3Po4(aq) = 6 H2O(l) + Ca3(Po4)2(s)