Chemilla's Treasure Quest
An Investgation Into Calculating Density
Chemilla was the best treasure hunter that had ever existed. She took precious metals from over 100 countries, but one day, she found three items in her collection that got misplaced. She had traveled all over the world for the past ten years to get the most beautiful and precious of metals. During those ten years, she never misplaced anything! She was infuriated! Chemilla divided her treasure into categories of copper, gold, aluminum, and iron. Because she didn’t want to send her unknown metals out to her treasure classifier who was a mere 2000 miles away, she decided to take matters into her own hands by using her awesome chemistry skills. She decided to find the density of all the objects and matching them up with the table she has hanging in her hideout.
Density of Substance (g/cm^3)
In this lab, you will be finding the data of how many grams each object weighs, what each object’s volume is, and by using the density formula (D= M/V), finding the density of each object. By using more calculations, you will eventually figure out which item is what element.
Your guiding question is- By identifying the density of each of the 3 solids, what are the substances of each of the objects using the table above?
Before getting started, Chemilla will provide you with some useful definitions.
Density- A measure of compactness of a substance.
Mass- A fundamental measure of the amount of matter in an object.
Volume- The amount of space an object occupies.
Solid- A sample of matter that retains its shape and density when not confined.
Element- An element is a substance which all have the same number of protons.
Substance- A Matter which has specific composition and properties.
Today, you will be helping Chemilla find the density of all four objects, by finding the density of each object, and matching the density with the numerical data on the table.
Safety Procedures and Equipment
Safety procedures and Safety equipment-
To perform this lab, the following safety equipment will be necessary
Gloves- It is advisable that you wear gloves during this experiment to air on the side of caution. The main concern is that nobody gets a metal allergic reaction during or after the experiment due to the metals they are handling. The metals may also scratch you at any point.
Apron- The apron is a mandate for most experiments and is also something that is used to air on the side of caution. It is advised you wear on so that your clothes won’t get wet or stained.
Safety Goggles- Safety goggles are another mandate for all experiments to protect your eyes and vision since they are sensitive to every substance.
Explanation of Safety procedures-
Wash your hands before and after the lab to ensure no other objects/ food/ substances get contaminated.
Do not touch your face or any exposed skin when you have started your experiment to avoid metal skin reactions.
Restrain any dangling jewelry, loose clothing, or long hair before the lab that might get caught in any equipment.
Report any accident (spill, breakage etc.) to the teacher, no matter how trivial, to ensure safety.
Scale that measures in grams
100 ml Graduated Cylinder
Flat surface to experiment of (counter, table etc.)
Recording device (iPad, Pen, Pencil, Paper etc.)
3 Post-it notes
Water or sink available
Copper circles or cube
Iron circles or cube
- Piece of Aluminum
Before you start this lab, make sure you have washed your hands, put on your gloves, goggles, and apron for safety reasons. During this lab, you will calculate the density of three objects and try to match the densities of this object to numerical data given to you in a table. Make sure you have all of your equipment set out and also be sure to have a recording device of hand. (iPad, Paper and pencil) Also before you start, get three post it notes and write object 1, 2, and 3 on them. When you are at this step, randomly place each of the objects of each of the post it notes so all unknown objects are now labeled.
To start off this experiment, create a table on your recording device that contains four columns and four rows. Your first column should be named “Object number”, your second column should be named “Mass (g)”, your third column should be measured “Volume (ml)”, and your fourth column should be labeled “Density (g/ml)”. On the other hand, your first row should all have their titles, your second row should say “Object 1”, your third row should say “Object 2”, and your fourth row should say “Object 3”. Now that you are done with your table, we can start the experiment.
The first step in this experiment will be collecting the mass of your three objects. The mass will be in grams. To do this, turn of your electronic scale and make sure that the monitor shows up at 0 grams. Gently place Object 1 on the scale, and record its mass in grams (g), before you remove it from the scale. You will record this data in the column you labeled “Mass (grams)”. Repeat the same step for the other two unknown objects. When you are done, press the power “off” button on the scale.
Once you have found the mass in grams, and have filled out your table, it is time to measure each object’s volume. Since none of the objects are perfectly shaped into cubes, prisms, or pyramids, you will find volume through a method called “water displacement”. To do water displacement, first using a sink, fill your graduated cylinder up to the 80 ml (milliliters) mark. Make sure that after your graduated cylinder contains water to put it on a flat surface. Once you have put your graduated cylinder that contains water on a flat surface, gently put in object 1 into the graduated cylinder. When you put your objects in, make sure to do it gently, so no excess water comes out of the graduated cylinder. As you might see, after putting the object in, the water level rose to a new milliliter mark on the side of the graduated cylinder. You will subtract your original 80 ml (without any objects) from the new water level. This end number is your volume. For example, if after putting the object in the water filled cylinder it rose to 110 ml, I would take the original amount (80 ml) and subtract it from 110 ml to get 30 ml, which is my volume. Make sure to record your volume for Object 1 of your table. Repeat for the other two objects. Make sure to empty and refill your graduated cylinder to 80 ml for each object. Also make sure to record your volume in ml.
Since you have found and filled out your table for the mass and volume for each object, it is time to find the density. To find density, you will use the equation, Density= Mass divided by Volume. To find the density for these objects, make sure you use a calculator to receive precise results. To find the density for object one, type in the numerical mass that is on your table, press the divide button, and then divide the mass by the numerical volume found on your table. Pay attention so you choose the correct mass and volume for each object. Once you have calculated the density, fill it in on your table. Repeat this step for the two other objects. After you find each density, make sure to hit the “reset button”. Record density in g/ml.
- Your table should be completely filled out now with each object’s mass, volume, and density. The last step is to match the density of each object to one of the objects on the table given. When you match the densities of the objects that you recorded and the values on the table, write the substance next to the “Object 1, Object 2, or Object 3” labels on your table. After matching this up, you are done! After you have finished make sure to wipe down, clean, and dry off the flat surface you did this experiment on , your graduated cylinder, and your scale. Put away your apron, goggles, and gloves when you have finished cleaning up.