Chemistry/Measuring Volume

Science 8 Laboratory Investigation MEASURING VOLUME

Purpose

To learn how to measure the volume of various objects by direct and indirect measurements, using a graduated cylinder.

Procedure: 1. Three types of graduated cylinders containing water have been put out for you: a 10 mL size, a 25 mL size and a 100 mL size. 2. There are six 10 mL graduated cylinders, each of which is numbered and each of which contains a different volume of water. DO NOT TIP OR SPILL ANY OF THE WATER! Make a volume reading for ONE of the 10 mL graduated cylinders and record in your Data Table both the volume and the number of the graduated cylinder. 3. There are six 25 mL graduated cylinders, each of which is numbered and each of which contains a different volume of water. DO NOT TIP OR SPILL ANY OF THE WATER! Make a volume reading for ONE of the 25 mL graduated cylinders and record in your Data Table both the volume and the number of the graduated cylinder. 4. There are six 100 mL graduated cylinders, each of which is numbered and each of which contains a different volume of water. DO NOT TIP OR SPILL ANY OF THE WATER! Make a volume reading for ONE of the 100 mL graduated cylinders and record in your Data Table both the volume and the number of the graduated cylinder. 5. Use a dropping pipet to fill a 10 mL graduated cylinder with exactly 4.6 mL of water. Show your teacher or teaching assistant. They will “initial” your Data Table, to confirm that you have done this. 6. Use a dropping pipet to fill a 25 mL graduated cylinder with exactly 6.2 mL of water. Show your teacher or teaching assistant. They will “initial” your Data Table, to confirm that you have done this. 7.(a) Measure the length, width and height of one of the blocks of aluminum put out for you. Make your measurements to the nearest 0.1 cm; that is, to the nearest 1 mm. Record your measurements in the Data Table. (b) Place exactly 20 mL of water in a 100 mL graduated cylinder and record this volume in your data Table. (c) Slightly tip the graduated cylinder and carefully slide the piece of aluminum into the water. (d) Read the volume shown in the graduated cylinder and record this volume in your Data Table.

Data Table

Step	Object	Measured volume (mL)
2	Number of 10 mL graduated cylinder = ________
	Volume of water in 10 mL graduated cylinder ---->
3	Number of 25 mL graduated cylinder = ________
	Volume of water in 25 mL graduated cylinder ---->
4	Number of 100 mL graduated cylinder = ________
	Volume of water in 100 mL graduated cylinder --->
5	I have put 4.6 mL of water in a 10 mL graduated cylinder.	Initialled by: _____________
6	I have put 6.2 mL of water in a 25 mL graduated cylinder.	Initialled by: _____________
7 (a)	Aluminum block measurements: length = ___________ cm width = ___________ cm height = ___________ cm
7 (b)	Volume of water initially in 100 mL cylinder ------->
7 (d)	Volume reading after putting in the aluminum ---->

Questions
1. The volume of the aluminum block can be calculated from the following mathematical formula.

VOLUME = LENGTH x WIDTH x HEIGHT

Use your values for step 7 (a) in your Data Table to calculate volume of the aluminum block. Show your work.

2. You can also calculate the volume of the aluminum block by the following VOLUME DISPLACEMENT method. Subtract the initial volume of water (7–b in your Data Table) from the volume of water shown after the aluminum block is placed in the graduated cylinder (7-d in your Data Table). The result is the volume of the aluminum.

3. The volume you calculated in question 1 should be equal to the volume you found in question 2. Do your two volumes seem to be close to each other? Explain your answer.

4. If you are given a small, irregularly-shaped, jagged piece of rock, which method will probably give you a more accurate value for the volume: the method used in question 1 or the method used in question 2? Explain your answer.

5. Which of the measurements you made in this laboratory investigation are DIRECT MEASUREMENTS and which are INDIRECT MEASUREMENTS?