Question

Pellets of sodium hydrogen Carbonate and anhydrous CuSO4 were put in petri-dishes and left in the open. What will be the observation?
DrBob222
From the wording I interpret the problem as stating EACH is in its own petridish. Anhydrous CuSO4 is grey in color. When left in the open it will pick up water of hydration to make CuSO4.5H2O and it turns from grey to blue in the process.