Calcium carbonate is also used in the purification of iron from iron ore in a blast furnace. The carbonate is calcined in situ to give calcium oxide, which forms a slag with various impurities present, and separates from the purified iron.
One re-hydrated package fills about 15-20 dishes. Mix 1 level teaspoon of dehydrated agar with 100 ml (3/8 cup) of water and then bring to a boil to make 100 ml of agar solution. Prepare Petri Dishes: Fill petri dishes to just cover the bottom. Typical 90-100mm dishes require 10-15 ml agar. Rotate the dish to obtain even surface coverage. Cover the dish immediately and let stand until firm. Store upside down in the refrigerator until ready to use.
drops of methylene blue in the âMâ hole, and potassium permanganate in the other. Be . careful not to let the dye solutions overflow onto the surface of the agar. Record the . time. _____ Obtain a second Petri dish from your instructor. Prepare it just like the first. Record the time and place this second Petri dish in the refrigerator. Record the time.