Measurements and the Process of Science

Learning Plan 1. Measurements and the Process of Science

Target Competency

1. Apply basic chemistry methods and measurements. (Ch.1)

Directions

Part A.
Choose something to observe in your environment (e.g., sugar dissolving in Kool Aid, pasta cooking, alka seltzer dissolving in water, vinegar reacting with baking soda, etc.).

Make a list of all the observations you can make (at least 10).
Now, from this list of observations, come up with a hypothesis that you can test.
Design an experiment that could be run to test your hypothesis.
Be sure to follow the steps of the scientific method in setting up your experimental report.

You do not need to perform the experiment. You will be graded on your initial observations, hypothesis and written experimental report.

Part B.

a. If we assume the density of blood is 1.060 g/mL, what is the mass of 6.56 pints of blood in grams?

b. A patient weighs 146 pounds and is to receive a drug at a dosage of 45.0 mg per kg of body weight.
The drug is supplied as a solution that contains 25.0 mg of drug per mL of solution.
How many mL of the drug should the patient receive?

c. A typical aspirin tablet contains 5.00 grains of pure aspirin analgesic compound. The rest of the tablet is starch. How many aspirin tablets can be made from 50.0 g of pure aspirin?

d. What Fahrenheit temperature corresponds to 37.0 degrees C?

e. If a person smokes 10.0 packs of cigarettes a week and each cigarette contains 5.00 mg of tar, how many weeks will she have to smoke to inhale 0.250 pounds of tar? [Use: 20 cigarettes = 1 pack]

f. A patient needs 0.300 g of a solid drug preparation per day. How many 10.0 mg tablets must be given to the patient per day?

Part C

In two paragraphs, discuss the terms precision and accuracy in relation to significant digits.

In your discussion, address how significant digits relate to the measuring device, and why rules for significant digits are needed for calculations involving measurements.