The Scientific Method

The Scientific Method

This experiment was performed by using a systematic approach to identify six unknown substances. In the first half of the experiment six unknown substances were observed than measured by determining volume, mass and density. The second half of the experiment the unknown were placed in a test tube and tested for solubility. It was determined that the six tubes contained coffee, potting soil, brown sugar, baby powder, baking soda, and powdered sugar. By the use of the scientific method each unknown subject could be identified.

Hypothesis:
The contents of unknown samplers are as follows: #1 coffee, #2 potting soil, #3 brown sugar, #4 baby powder, #5 baking soda, #6 powdered sugar.

Material List:
Digital Scale
50 ml Cylinder
Safety Goggles
Spatula
6 Test Tubes
Magnifier
Rubber Stopper
Test Tube Rack
Marking Pencil
Test Tube Cleaning Brush

Procedure: The unknown substances were removed from a bag. Next, volume, density, and mass were calculated using small paper boats, a digital scale, and a formula which called to divide the mass by the volume. Then, the texture, shape and appearance of each substance was observed and recorded. Lastly, each substance was tested for solubility in distilled water.

Scientific Method Data Table 1
Unknown Sampler
1
2
3
4
5
6
Hypothesis
Coffee
Potting Soil
Brown Sugar
Baby Powder
Baking Soda
Powdered Sugar
Color
Brown
Dark Brown
Light Brown
White
White
White
Texture
Rough
Clumps, rocky
Gritty
Soft/Smooth
Soft/Smooth
Soft/Smooth
Shape
Small particles, visible
Large Particles
Very small particles, amorphous
Very small particles
Large particles
Visible particles
Smell
Coffee beans
Dirt
Food/spice
Baby powder
No smell
No smell
Soluble
Yes
No
Yes
Yes
Yes
Yes
Density
.31
.3
.3
.61
.4
.46
Conclusion
Correct
Correct
Correct
Correct
Unsure Unsure

Data Table 2: Calculating Density of Unknown Samples
Mass of Unknown
Sample (g) Volume (cm) Density (g/cm)
Unknown Sampler# 1 = 0.4
1.3
.31
Unknown Sampler#2= 0.5
1.5
.3
Unknown Sampler#3=0.5
1.5
.3
Unknown Sampler#4=0.8
1.3
.61
Unknown Sampler#5=0.6
1.5
.4
Unknown Sampler#5=0.6
1.3
.46 Discussion
Based off of observations of color, shape, and texture and smell hypothesis is accurate and correct for unknown samples 1-6.

In conclusion based off of color, smell, and texture the hypothesis for unknown substances 1-4 are correct, but based off of these same observations substances 5 and 6 are questionable.

Questions:

1. Which of the six measures in the experiment yielded quantitative data? What specifically about the measures was quantitative? Quantitative data is data that can be measured numerically, out of the six measures in the experiment volume, mass, and density would be considered quantitative since these measures can be measured numerically unlike any other from the experiment.
2. Which unknowns are you confident that you correctly identified? What specific test was crucial in confidence? I am confident that I have correctly identified unknown substances 1-4 based off of color, texture, smell and solubility these measures were crucial in my confidence of my hypothesis.
3. One of the most important and unique steps in the scientific method is the ability to create a new hypothesis if your results do not support your original ideas. What areas in your life, other than in science class, do you think this type of step would be helpful? I am a mother and frequently find myself in the kitchen cooking and trying out new recipes that taste good but are still nutritious (children can be very picky) I would say in terms of a new recipe that I am trying- If my idea is that my children would like to try something new I would test it out by serving it to them, and in the case that my children do not like it I would try again maybe add some ingredients or take something out in hopes that the end result would be for my kids to enjoy the meal while getting all of the nutrition that kids need.
4. What additional test could you perform to assist in the identification of these unknown samples? Melting, boiling, or even chemical test may be performed.
5. Which of the seven tests performed was the most challenging: The most challenging test for me was the shape test, I found this most difficult because although I had the magnifier I still had trouble distinguishing what it was that I actually saw as I was examining each substance, however once I examined each substance individually I compared what I saw and could most definitely see the difference between large and small particles.