Students will determine the density of 2 unknown liquids by collecting mass and volume data. Each group of students will be given a different volume of the liquids to measure, they will combine their data to create a graph. Using the graph students will determine the density of the two liquids by calculating the slope of the two lines. Students will also use a graphing calculator to determine the slope of the two lines. This activity is a wonderful way to integrate Chemistry and Algebra 2 because the measuring of density is simple enough to do in an Algebra 2 class and using a hand drawn graph and a calculator to determine the slope are skills students need to master for Algebra 2. It also shows students a use for slope in a data collection scenario.
- Students will accurately measure the volume and mass of a liquid.
- Students will graph the class data by hand and determine the slope of the lines.
- Students will graph the class data using a graphing calculator and determine the slope of the lines.
- Students will identify the slope of the lines as the density of the liquids.
- Students will identify the liquids from their respective densities.
- 1.01: Design, conduct and analyze investigations to answer questions related to chemistry.
- 1.02 Analyze reports of scientific investigations from an informed scientifically-literate viewpoint including considerations of:
- 1.03 Analyze experimental designs with regard to safety and use safe procedures in laboratory investigations:
- 2.04 Identify substances using their physical properties: Density
Algebra 2 SCOS:
- 2.04 Create and use best-fit mathematical models of linear, exponential, and quadratic functions to solve problems involving sets of data.
Classroom Time Required:
- 2 liquids
- 10mL and 25mL graduated cylinders
- Graphing Calculators
- Graph Paper
- Reference Tables with densities of liquids.
The teacher should make sure that students can calculate density. They must also be able to calculate the slope of a line and use a graphing calculator to input data and graph it. Teach/Review how to calculate percent error.
- The teacher should begin with how to calculate the density of a liquid.
- The teacher should also explain how to accurately measure mass and volume of a liquid.
- The teacher should review how to determine the slope of a line from a graph and on the calculator.
- The students will collect and accurately record mass and volume data for 2 liquids.
- The students should write their data on the board or overhead for all to copy.
- Once all data is collected the students are to complete the post lab activities.
- The teacher should use the class data to determine the slope of the 2 lines of data provided by the students for checking their answers later.
- Post lab questions are provided.
- Line of best fit
- Linear regression
- Stat plot
- Percent error.
Websites & Resources:
The Texas Instruments website is a great resource for calculators and for instructions on how to use the calculator if you or your students are not familiar. ( www.ti.com)
This activity works best with collaboration between science and math teachers, although both can do it separately.