In order to have clean glassware for lab work, someone needs to go through many steps of washing the flasks and beakers.

Here is Amy, ready to start this work!

Here is the "recipe" for clean glassware:

1. Wash the glassware with Alconox, a biodegradable detergent soap.
   
   
2. Rinse with tap water.
   
   
3. Soak the glassware in a basic Contrad solution of potassium hydroxide for four hours.
   
   
4. Rinse with tap water at least six times.
   
   
5. Do an "acid rinse" by using hydrochloric acid to rinse the glassware inside and out.
   
   
6. Rinse with de-ionized water.
   
   
7. Rinse again with hydrochloric acid inside and out.
   
   
8. Rinse with de-ionized water 6 more times.
   
   
9. Bake for four hours in a Muffle furnace at 550C° , the maximum temperature for this glassware.
   
   
10. When the glassware has cooled to 100-150° C, cover the tops with aluminum foil caps that have been "cooked" for four hours.

OK, how long will it take Amy to do a "load" of glassware?

Amy is a fast worker, but it still takes her 1.5 minutes to wash or rinse the small flask, 2 minutes to wash or rinse the medium-sized flask, and 2.5 minutes to wash or rinse the large flask.

Here are the flasks she has to wash:

As you can see, there are 3 large flasks, 3 medium-sized flasks, and 3 small ones.

So, how long will it take her to clean this amount of glassware, from beginning with the detergent wash to removing the glassware from the oven (steps 1-9 above)?

There are many ways to solve this problem. Here are some hints:

You might want to count the number of times each flask has to be washed or rinsed. Each one is washed or rinsed separately.

You will need to add in the soaking time and the time the flasks spend in the oven. All the flasks will fit into the oven at the same time.

Work with someone else to talk about ways in which to solve this problem!

Here is Amy, when her work is done!

Michele takes the clean glassware out of the oven. The glassware is ready to be used again!