lab2

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Designing an Experiment Materials:  2 beakers or empty jars that can hold hot water  Hot water (use hotplate, kitchen stove, or electric pot)  Kitchen scale  Measuring cup  Camera  Borax (Fig. 1)  Handwritten name tag (Fig. 2)  2 pipe cleaners  Thread/string  2 bamboo sticks  Food coloring (optional)  Cardboard or something to cover the beakers/jars Fig. 1. Box of borax (~$5). *Please feel free to be creative and use what you have around the house. YouTube videos: Search for “how to make borax crystals.” There are many videos you can watch before you begin. Instructions: Create two different size crystals by changing only 1 variable or condition. For example, you can change the amount of borax you use or change the rate of dissolution or cooling. Remember to keep everything else the same when you make two crystals. Define your hypothesis and test it. How to make crystals: 1. Twist the pipe cleaner to a desired shape. The two pipe cleaners should look identical. Weigh each pipe cleaner and record it on table 1. Tie a piece of thread to the pipe cleaner and then to a bamboo stick. 2. Create 1 crystal at a time. The amount of water and borax you use will depend on the size of your containers (beakers or jars). In the lab, we typically use 350 ml of water and 90-100 grams of Borax (Fig. 2). Record the amount of water and the weight of borax (in grams) you use on table 1. 3. You can create a crystal in many different ways. It will depend on what you are using at home. You can heat up the water in a beaker then add borax or you can boil the water first and add borax powder. You may add food coloring of your choice. 4. Insert the pipe cleaner and cover the beaker/jar with a piece of cardboard. Set it aside.  ENVR1401/GEOL1405 5. Repeat the steps 2-4 for the second crystal. With the exception of 1 variable, everything else must stay the same for the second crystal. Label each beaker (crystal 1 or crystal 2), take a photograph with your student ID or name tag, and set them aside for overnight. Table 1. Summary table for crystal 1 and 2. Crystal 1 Crystal 2 Weight of pipe cleaner (g) Volume of water (ml) Amount of Borax used (g) Weight of crystal with pipe cleaner (g) Weight of crystal (g) 6. Carefully take out each crystal from the beaker. Let them dry. Once they are dry, weigh and record it on table 1. Calculate the weight of the crystal by subtracting the weight of pipe cleaner and record it on table 1. Take a photograph of each one with your student ID or name tag. Lab Report: Create one typed lab report. The lab report should contain the following components:  Title  Name and date  Introduction – include your hypothesis  Materials and methods – do not copy and paste the instructions; include 1 photo with caption  Results – include 2 photos with captions and table 1  Discussion  Conclusion When completed, submit your Word document or pdf file to eCampus using the Lab 2 link. Fig. 2. Borax crystal made with 350 ml of water and 92 grams of Borax.

    • 3 years ago
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