A white crystalline compound is analyzed and found to have the following composition: 33.8% Na, 17.7% C, 47.0% O.

(a) Calculate the empirical formula of this compound.

(b) A solution is made by dissolving 0.500 g of the compound in 20.0 g water. This solution conducts an electric current and has a freezing point of -1.01 °C. What is the formula of the white solid? Write an equation that shows its dissociation in water solution.