Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

# Density Lab

## Determining the Density of Irregular Solids

#### Purpose of the lab

Determine the density of three different IRREGULAR SOLIDS

#### Materials

• 50 mL Graduated Cylinder
• 100 mL Graduated Cylinder
• Triple beam Balance
• 3 rubber Stoppers of each size
• triple beam balance

#### Determine the density of different IRREGULAR SOLIDS.

1. Measure the mass of one of the rubber stoppers using the triple beam balance.
2. Record this value in your data table
3. Fill the 50 cm3 graduated cylinder with SOME water (between 25 and 35 cm3
4. Record the exact initial volume of water.
5. Carefully insert the solid in the graduated cylinder.
6. Measure the volume of water + object.
7. Record the final volume in your table. (object + water)
8. Calculate the volume of the object based on your measurements.
9. Calculate the density of your metal sample and compare this to the table of metals and their densities found in the References Section of this handout.
10. Repeat the procedure for each sample you have and complete the data table.

#### Lab Setup

Draw snapshots of the step by step for one of the trials.

LAB SETUP IS NOT A COLLECTION OF LAB EQUIPMENT . You need to show HOW those items were arranged in order to perform the lab.

#### Determine the density of different LIQUIDS

For each liquid follow the instructions below:

for the WATER DENSITY:

SHOW YOUR CALCULATIONS WITHIN THE STEP BY STEP

1. Find the mass of the empty graduated cylinder that has the label “water”.
2. Fill the graduated cylinder with some DISTILLED WATER. (between 30 and 40 mL. Record the volume in the correspondent cell
3. Find the mass of the water and graduated cylinder. record
4. Find the mass of just the water (#3-#1). Record on the tableCALCULATION:
5. Find the density of water at room temperature.CALCULATIONS:

for the rest of the liquids

REPEAT STEPS 1-5 FOR THE REST OF THE LIQUIDS, INCLUDE YOUR CALCULATIONS AS WELL

SHOW YOUR CALCULATIONS WITHIN THE STEP BY STEP

DATA TABLE:

COMPLETE THE DATA TABLE BELOW WITH THE MEASUREMENTS AND CALCULATIONS ABOVE

## Post‐lab Analysis Questions

Based on your calculations and the reference data, what is the identity of your metals?

1.        Reflective Conclusion – Summarize your experience with the lab. What you can do better in the future, etc.  Ideally this would be more along the lines of a small paragraph or two, not just a single sentence.
2. The density of silver (Ag) is 10.5 g/cm3.  Find the mass of Ag that occupies 965 cm3 of space.
3. Under certain conditions, oxygen gas (O2) has a density of 0.00134 g/mL.  Find the volume occupied by 250.0 g of O2 under the same conditions.
4. Find the volume that 35.2 g of carbon tetrachloride (CCl4) will occupy if it has a density of 1.60 g/mL.
5. 30.0 g of each of the following acids are needed.  Find the volume of each that must be measured out in a graduated cylinder.
1. hydrochloric acid (HCl), density = 1.164 g/mL
2. sulfuric acid (H2SO4), density = 1.834 g/mL
3. nitric acid (HNO3), density = 1.251 g/mL
6. A rectangular block of lead (Pb) measures 20.0 mm X 30.0 mm X 45.0 mm.  If the density of Pb is 11.34 g/cm3, calculate the mass of the block.
7. An irregularly-shaped sample of aluminum (Al) is put on a balance and found to have a mass of 43.6 g.  The student decides to use the water-displacement method to find the volume.  The initial volume reading is  25.5 mL and, after the Al sample is added, the water level has risen to 41.7 mL.  Find the density of the Al sample in g/cm3.  (Remember:  1 mL = 1 cm3.)
8. A rectangular metal block is provided to you in the lab, with a measured mass of 39.5 g.  If the dimensions of the block are 12.68 cm by 2.36 cm by 2.48 cm, what is the density (in g/cm3) of the metal?
9. A 2.75 g sample of a substance occupies a volume of 2.5 cm3.  Find its density in g/cm3.
10. The density of ethanol is 0.789 g/mL.  Find the mass of a sample of ethanol that has a volume of 150.0 mL.
 Metal /non Metal Density  (g/cm3) Aluminum 2.64 Brass 8.56 Copper 8.94 Lead 11.342 Zinc 7.14 Acetone 0.79 Ethyl Alcohol 0.785 Water 1.00