Double Displacement Reactions

____Ca(OH)2 + _____ H3PO4

it forms calcium phosphate (Ca3 PO4 and water (HOH)

To determine the balanced equation for the double displacement reaction between calcium hydroxide (Ca(OH)2) and phosphoric acid (H3PO4) that forms calcium phosphate (Ca3(PO4)2) and water (H2O), we need to follow certain steps.

Step 1: Write the chemical formulas for the reactants and products.
Calcium hydroxide: Ca(OH)2
Phosphoric acid: H3PO4
Calcium phosphate: Ca3(PO4)2
Water: H2O (which is HOH in the balanced equation)

Step 2: Determine the cations (positive ions) and the anions (negative ions) present.

In Ca(OH)2:
- Calcium ion (cation): Ca2+
- Hydroxide ion (anion): OH-

In H3PO4:
- Hydrogen ion (cation): H+
- Phosphate ion (anion): PO43-

Step 3: Swap the anions between the cations. The cation from one compound combines with the anion from the other compound.

Ca2+ combines with PO43- to form Ca3(PO4)2
2OH- combines with 2H+ to form 2H2O

Step 4: Balance the equation by adjusting the coefficients (numbers in front of the chemical formulas) to ensure the same number and types of atoms on both sides of the equation.

Ca(OH)2 + H3PO4 → Ca3(PO4)2 + H2O

This is the balanced equation for the double displacement reaction between Ca(OH)2 and H3PO4 that forms Ca3(PO4)2 and H2O.