Suppose you are working for a pharmaceutical company, and your boss has tasked you with identifying the contents of a bottle containing an unknown white crystalline compound. You have narrowed down the possibilities to sodium carbonate (Na2CO3) and sodium oxalate (Na2C2O4). Sodium carbonate is relatively harmless (a common ingredient in commercial water softeners), but sodium oxalate is extremely toxic to humans; it is therefore very important that you properly identify the unknown compound. You perform an experiment, and your results show the compound is about 43% sodium by mass. Use this information to identify your compound.