Journal Entry:
Kidney stones are solid blockages that sometimes occur in the kidney. Below is the chemical equation for a double exchange reaction between calcium chloride and sodium oxalate that results in the formation of one type of kidney stone.

CaCl₂(aq) + Na₂C₂O₄(aq) → 2NaCl(aq) + CaC₂O₄(s)

1. What do you expect to see in the beaker if you complete this reaction?

2.Which compound creates the kidney stone? What is your reasoning?

Learning Intentions

• We will learn what a precipitation reaction is.
• We will learn how to write complete and net ionic equations for precipitation reactions.
• We will learn what a spectator ion is and be able to identify one.

Closing Task:

You can determine cations and anions in a compound and make a prediction about which ions will form precipitates and which will be spectators in a precipitation reaction. 

Content Standards being covered:

Student understands what the letters and numbers stand for in a compound formula, can use those letter and numbers to determine how many of each type of element there are in a formula.

Student can create mathematical representations of chemical reactions and use them to make calculations about products and reactants.

Students can use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction. (HS-PS1-7 and CCC Energy and Matter)