The main component of the crystals in taro that causes itching is calcium oxalate (CaC₂O₄). The solubility of calcium oxalate in water is 6.66×10^–3 g/L at room temperature. What is this concentration in (m/v)%, in ppm, and in molarity?

• A. 6.66×10^–4% (m/v); 0.666 ppm; 5.20×10^–4 M
• B. 6.66×10^–3% (m/v); 6.66 ppm; 5.20×10^–5 M
• C. 6.66×10^–4% (m/v); 6.66 ppm; 5.20×10^–5 M
• D. 6.66×10^–3% (m/v); 0.666 ppm; 5.20×10^–4 M
• E. 6.66×10^–5% (m/v); 66.6 ppm; 5.20×10^–3 M

Answer: (C)