Question

Many plants are poisonous because their stems and leaves contain oxalic acid, H2C2O4, or sodium oxalate, Na2C2O4. When ingested, these substances cause swelling of the respiratory tract and suffocation. A standard analysis for determining the amount of oxalate ion, C2O 2− 4 , in a sample is to precipitate this species as calcium oxalate, which is insoluble in water. Write the net ionic equation for the reaction between sodium oxalate and calcium chloride, CaCl2, in aqueous solution.

Answer 1

Step-by-step explanation:

Calcium chloride is a soluble salt which dissociates into calcium and chloride ions when dissolved in water.

CaCl₂(aq) ----> Ca²⁺(aq) + 2Cl⁻(aq)

Similarly, sodium oxalate when dissolved in water dissociates into sodium and oxalate ions.

Na₂CO₄(aq) ----> 2Na⁺(aq) + C₂O₄²⁻(aq)

However, in a double displacement reaction where the two solutions of the salts are mixed, the insoluble salt calcium oxalate is precipitated. The net ionic equation for the reaction is shown below:

Ca²⁺(aq) + C₂O₄²⁻(aq) ----> CaC₂O₄(s)