I need an explanation for this Biology question to help me study.
Complete the lab and fill out the document attched with the question.
- select baby powder, baking soda, corn starch, powdered sugar, and zinc oxide. Set the other samples aside for later use.
Note: Zinc oxide is a common ingredient in some sunscreens, diaper ointments and makeup.
- Review Data Table 2–6 which list a series of tests that will be applied later in the experiment to identify unknown substances.
Test for Appearance:
- With scissors and a ruler, cut a 10 x 10 cm piece of paper. Label the paper “baby powder.”
- Open the vial containing baby powder. Transfer all of the contents of the vial to the labeled piece of paper.
- Describe the appearance of the baby powder and record your observations in Data Table 2.
Note: Close visual observation may offer subtle differences among the samples.
- Repeat steps 4–6 for each of the substances in the remaining 4 vials (baking soda, corn starch, powdered sugar, and zinc oxide). Be sure to label each piece of paper appropriately.
Test for Scent:
- Test the scent of the baby powder by using your hand to gently waft the odors toward your nose. Record observed scent in Data Table 3.
Note: Do not directly inhale any of the substances. Waft the odors toward your nose using a circular motion with your hand at a distance of 6-8 inches.
- Repeat step 8 for the four remaining substances.
Test for Mass (g):
- Locate a digital scale. Turn on the scale, and set the scale to grams.
- Using scissors cut a piece of paper that is about 5 x 5 cm2, just big enough to cover the scale. This will be your weigh paper.
- Using scissors cut a piece of paper that is about 10 x 10 cm and label it Baby Powder. This will be the paper you use to pour out the baby powder onto.
- Place the piece of paper on the scale. Notice that the mass of the paper in grams is displayed.
- Press the power button once to tare the scale to read 0.00 g.
Note: The scale will read 0.00 g with the piece of paper on top. The scale is set to automatically turn off after some time. If this occurs, simply press the power button to turn the scale back on. The scale will again read zero.
- Locate a kitchen knife and a ¼-teaspoon.
- Pour the contents of the vial that contains the baby powder onto the 10 x 10 cm2.
- Use the knife and measuring spoon to collect a heaping spoonful of baby powder from the 10 x 10 cm paper.
- Scrape the excess powder from the spoon and back onto the paper labeled baby powder. The sample of baby powder should be perfectly even with the top of the spoon, as shown in Figure 2.
- Reserve the excess baby powder for future steps.