Education Technology

# Activities

• ##### Subject Area

• Science: Chemistry: Gases, Liquids and Solids
• Science: Forensics: Data Analysis
• Math: Algebra I: Data Analysis
• Math: Middle Grades Math: Problem Solving
• Math: PreAlgebra: Probability, Statistics and Data Analysis
• Math: Statistics: Data Analysis

9-12

100 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition
• TI-84 Plus C Silver Edition
• TI-84 Plus CE
• ##### Software

TI Connect™
TI Connect™ CE

• ##### Accessories

Sensor - Temperature
TI Connectivity Cable

## Forensics Case 11 - Ashes to Ashes: Using evaporation rate to identify an unknown liquid

#### Activity Overview

In this activity, students understand that evaporation rate is a characteristic property of a liquid. Based on this fact, they identify the solution and the likely accelerant in a case of arson. They compare the evaporation rates of the accelerants found with the suspects with those near the crime site.

#### Key Steps

• Each graph that students make will show a decrease of temperature as each liquid evaporates. Then they will compare the temperature differences to identify the suspect who had traces of the matching accelerant.

• The graphs of each unknown is compared to the known sample found at the crime scene. Which substance belonging to which suspect came closest?