The Hand Warmer Design Challenge Where does the heat come from? AP Chemistry: Laboratory Spring 2016

Central Challenge Design a hand warmer that meets the following criteria: 1. Increases in temperature by 20oC after salt (ionic compound) is dissolved in 50.0 mL water 2. Costs as little as possible to make 3. Uses chemicals that are safe and environmentally friendly *Animate

Investigation Timeline Part 1: Calorimetry Practice Part 2: Calorimeter Calibration Part 3: Data Collection & Experimental Procedure

Investigation Timeline Part 1: Calorimetry Practice Part 2: Calorimeter Calibration Part 3: Data Collection & Experimental Procedure

Report Guidelines: Lab Notebook Pages Pre-lab questions (complete, correct) DETAILED procedure (numbered steps, materials/equipment, amounts needed) Data, Observations, & Analysis (mass, T, ΔT) Part 1: Calorimetry Practice (MgSO4) Part 2: Calorimeter Calibration Part 3: Experimental Procedure Organized in tables! Calculations Enthalpy (q): hot, cold, calorimeter, solution, reaction Calorimeter constant C ΔHsoln Organized in step by step format! Post-lab questions (complete, correct) Will only grade ONE set of yellow pages (chosen at random) from each team (ease of grading) – does not mean to directly copy, especially pre/post lab Qs Emphasis: neat, organized, easy to follow, completed

Report Guidelines: Presentation (10 min) Describe all factors considered to meet criteria Explain rationale for choosing one chemical and not the others Possible Organization: Overview of experiment & claim Experimental Evidence + Cost & Safety Analysis Reasoning to support claim BONUS: sales pitch See “Argumentation & Documentation” from lab manual, pg. 103 PowerPoint presentation Full report (NB pages + presentation) is 35 points [20 points for presentation, 15 points for lab notebook pages] – show rubric