Question

What is the balanced reaction equation between calcium hydroxide and phosphoric acid (`Ca(OH)_2andH_3PO_4`)?

Answer 1

It helps to write out the ions

Explanation:

Since `H` is always `H^+` we may conclude that the rest is `PO_4^-3`
Also The `OH`-part is `OH^-`, so that calcium is `Ca^(2+`

To make this work we need `3Ca^(2+)` to balance with `2PO_4^(3-)`

Or: `3Ca^(2+)+2PO_4^(3-) -> Ca_3(PO_4)_2`

And for the whole equation:

`3Ca(OH)_3+2H_3PO_4->Ca_3(PO_4)_2+3H_2O`