advertisement

Name: ___________________ Date: _______________ Page: ______ Volume and Density Lab Low Density = parts are farther apart High Density = parts are close together Background: Density is a measure of how much mass there is in a certain volume of a substance. In other words, density is how tightly packed the particles are that make up solids, liquids, and gases. The closer the particles are, the more density an object has. If you know the mass and volume of an object, you can calculate its density. Look at the example below. Classroom #1 Classroom #2 Classroom #1 has a larger number of students (mass) in the same amount of space (volume) as classroom #2. Classroom #1 has a larger density of students since they are more tightly packed into their room compared to room #2. Objective/Purpose: Formulas: Materials: To determine if air has mass. To examine the relationship between mass, volume, & density. Volume of cylinder: πr2h graduated cylinder beaker digital scale calculator Volume of cube: Density: lwh mass ÷ volume 2 pennies (stacked) 1 marble 1 die 1 plastic prism Part A: Determining density mathematically. You will be calculating the density of a prism, a die, 2 pennies, and a marble using a formula. What does ‘density’ mean? Predict which object (prism, die, 2 pennies, marble) you think will be the most dense. __________ Provide a quick explanation for why you chose the item you did. Use the digital scales to determine the mass of each of the given items (plastic prism, die, pennies, and marble). Input the values in the chart. Use the given mathematical formulas to determine the volume of the prism and die. Input the values in the chart. Use the density formula to determine the mathematical density for each of the given items. If you did not predict the correct item with the highest density, what did you learn? If you did predict the correct item with the highest density, try to think of an everyday item in the classroom that would be even more dense. __________ Part A: Mass Volume Density Plastic prism Dice Pennies Marble Part B: Determining the density experimentally. You will use an experiment to find the density of objects and compare to your results in part A. This method is used to find volume when objects are hard to measure with rulers. Add 500mL of water to the beaker. Add the plastic prism and measure the new volume. If the prism wants to float, hold it down enough to cover the prism with water but not dipping your finger into the water. Record the new volume in the appropriate place on the chart. Subtract 500mL from the new volume to determine the volume of the prism. Remove the prism from the beaker. Add 25 mL to the graduated cylinder. Add the marble to the cylinder and find the new volume. Record the volume in the chart. Remove the marble from the graduated cylinder and make sure there is still 25 mL of water left. Repeat steps 7-9 with the pennies and dice. Use the mass determined in Part A and the experimental volume calculated in Part B to determine the experimental density. Part B: Initial volume Plastic prism Volume of cylinder + item Volume of item = (volume of cylinder + item) – initial volume Experimental Density 500 mL in beaker Dice 25mL Penny 25mL Marble 25mL Questions/Results: Answer on a separate sheet. 1. How did the experimental volumes in Part B compare to the mathematical volumes calculated in Part A? 2. How did the experimental densities in Part B compare to the mathematical densities calculated in Part A? 3. Which method for finding volume do you think is more accurate? Explain your answer. 4. In a few sentences, explain what this lab activity has to do with what we are studying in science about the air in the atmosphere. 5. What is the relationship between the density of the air and the amount of oxygen available to breathe? (Hint: As the density of air increases….) 6. Why does the density of the air increase as you get closer to Earth’s surface?