Lab Investigation: Making Coffee in perfect concentrations

Class Inquiry Question

What is the appropriate mass of coffee beans required to make the perfect cup of coffee?

Background Research

The three main phases of matter are solids, liquids, and gases. Solid particles vibrate while locked in place. As they receive more energy (usually through heat), particle speed increases. Once the particles have enough energy they break apart and slide past each other as a liquid. Liquids are often used as solvents in the creation of solutions. Solvents serve to dissolve the solute (in this case, coffee grinds) and create a given solution with an appropriate concentration.

Purpose: Determine the concentration of a properly made cup of coffee.

Method: Make a solution of coffee with perfect concentration and taste it to decide whether the correct strength has been reached.

Materials:

Coffee Beans Magic Bullet Grinder

Water Digital Scale

Pyrex Beaker Mug 3 oz. Dixie Cup

Hot Plate French Press

Thermometer Graduated Cylinder

State your hypothesis

Write your hypothesis that predicts a plausible outcome to your problem; please use the guidelines below:

§  “If…, then…, because…” format

Example: If there is an increase in the voltage, then the current will increase because…

I think that ______when food coloring is added to a cup of cold water and a cup of hot water because ______

______.

Materials

Create a list of materials to test the problem. List the materials. Make sure to include how much or how many of each thing you will need.

NOTE: Modify this list as needed throughout the lab.

Methods

Write all procedures (in third person) so that it is very clear for others to follow, like so:

Results/Observations

1.  Describe what happened as the coffee beans were physically broken down into coffee grinds. How did this help speed up the coffee-making process?

2.  Describe how the color of the coffee changed as the French Press was pushed further into the coffeemaker? What does the color indicate about the strength of the coffee? What is this called?

3.  Why do you think it is essential to use hot water in the coffee brewing process rather than cold or luke-warm water?

4. There were several variables in this experiment:

·  Amount of water in the French Press

·  Amount of coffee beans used

·  Temperature of the water

·  The speed at which the French Press was pushed down

Pick two of these variables and explain why it was essential to accurately measure exactly what value the variable constituted?

Explain it With Atoms & molecules

You saw an animation of water molecules being heated and cooled. Now you can draw your own molecular of what happens when coffee grinds are dissolved in water. Be sure to label your molecules!

5. Based on your observations, fill in the blanks with the words increases or decreases.

·  Heating a substance ______molecular motion.

·  Cooling a substance ______molecular motion.

·  As the grams of solute are increased the concentration of coffee ______.

·  As the milliliters of solvent are increased, the concentration of coffee ______.

6.  Using circles to represent water molecules, draw a model of the molecules in cold and hot water.

·  Use motion lines to show the speed of the molecules.

·  Consider the space between molecules in each temperature of water.

Form a conclusion

What was your hypothesis? Was your hypothesis correct or incorrect? ANSWER BOTH QUESTIONS IN ONE SENTENCE.
My hypothesis was ______(correct/incorrect) because I originally thought ______
______
______
______

Conclusion Rubric

1 point / 2 points
Hypothesis / States whether hypothesis
is right or wrong / States whether the hypothesis is right or wrong and restates the hypothesis
Data / Some data mentioned but
not clearly explained / Data clearly referenced and used to explain why hypothesis is right/wrong
Scientific Language / Some scientific language is
used incorrectly or difficult
to understand / Scientific language used to clearly explain the results of the lab
Follow Up / Unclear explanation of how the lab went. No suggested
changes / Clearly explains problems with the lab and changes to be made
Paragraph Format / Written in paragraph format but with incomplete sentences. Many grammar and spelling errors. / Written in paragraph format with at least 5 COMPLETE sentences. Few spelling/grammar errors.

Total Score: ______/ 12