# Find total ionic (balanced equation) for this particular reaction.

In summary, the total ionic (balanced) equation of the reaction between calcium hydroxide and phosphoric acid in aqueous solution is 3Ca(OH)2 + 2H3PO4 --> Ca3(PO4)2 + 6H2O. The solubility rules must be considered in determining which compounds will break up in aqueous solutions, and in this case, phosphoric acid and calcium phosphate are both considered insoluble.

## Homework Statement

Find the total ionic (balanced) equation of the reaction of calcium hydroxide and phosphoric acid in aqueous solution.

Solubility rules

## The Attempt at a Solution

First, I balanced the reaction.
3Ca(OH)2 + 2H3PO4 --> Ca3(PO4)2 + 6H2O
The part I'm stuck at is I don't know what to break up and what to leave. I know the solubility rules, but for some reason I keep getting this question wrong.

I know that Ca(OH)2 can break up into 3Ca2+ + 6OH-
But is that the only one that breaks up?

No idea what the correct answer is, as unfortunately it depends on what the teacher had on mind

Calcium hydroxide is weakly soluble (so mostly present as a solid), but it is a strong base (so it is 100% dissociated).

Phosphoric acid is a weak acid, so in typical solution it will be dissociated only partially, and only the first proton will be dissociated in substantial amounts (for example in 1M solution about 8%), yet it can react all the way down to PO43-.

Apparently you are expected to ignore some of these information and give answer based on some general (but not always correct) rules.

Thank you so much. I figured it out. They wanted me to look as phosphoric acid and calcium phosphate, both as insoluble. Thanks again!

## What is a total ionic equation?

A total ionic equation is a chemical equation that shows all of the ions present in a reaction, including those that are spectator ions. It is written in ionic form, with the compounds dissociated into their individual ions.

## Why is it important to write a total ionic equation?

Writing a total ionic equation allows us to see the individual ions involved in a reaction and how they interact with each other. This can help us better understand the underlying chemistry and predict the outcome of a reaction.

## What is a balanced equation?

A balanced equation is an equation in which the number of atoms of each element is equal on both sides. This is important because it follows the law of conservation of mass, meaning that no atoms are created or destroyed during a chemical reaction.

## How do you find the total ionic equation for a specific reaction?

To find the total ionic equation, you first need to write the balanced equation for the reaction. Then, you need to identify the ionic compounds and break them down into their individual ions. Finally, write the total ionic equation by combining the ions that are involved in the reaction.

## What are spectator ions?

Spectator ions are ions that are present in a reaction but do not participate in the actual chemical change. They remain in the same form on both sides of the equation and do not affect the overall outcome of the reaction.

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