How would you quickly determine whether a cleaning

agentcontained sodium carbonate or sodium phosphate?

The answer is explained below

Explanation:

If you add dilute HCl (Hydrochloric Acid) to the solution, and you see fizzing, then it is the carbonate. I would recommend doing this under a fume hood, as HCl has a wicked smell, and can make a few people sick to their stomach (however, you probably won't be using 12M concentrated HCl)