Entry Task Friday May 20 th How many grams of NaOH will you need to produce 50 kJ of energy using the following equation? 2 NaOH (aq) + H 2 SO 4 (aq) → 2 Na 2 SO 4 (aq) +2 H 2 O (l) ΔH = -114 kJ/mol *Collecting Heats of Solution Lab

Agenda  Collect Heats of Solution Lab  Discuss the Thermochemical Project  Time to work on Project

Thermo-Can Design Project

Thermo-Can Project Overview  You will be developing a concept for a portable food/beverage container that utilizes a chemical reaction to heat or cool food anytime and anywhere.  v=Y3_Rh_tJWH8&feature=fvw v=Y3_Rh_tJWH8&feature=fvw

 Inside is a can of food surrounded by an outer can  In the space between the two cans is a water bag and processed granular limestone  When you puncture the can, these two substances mix and create an exothermic reaction, heating your food!

You Will:  Choose your favorite food that needs a heat/ cold source, decide on an amount of food, and desired temp change (ΔT).  Research a chemical reaction with an appropriate ΔH that you will use in your Thermo-Can  Calculate the amount of reactants needed for desired heat change  Design the container and describe how it will work  Create a 4-6 minute marketing presentation (powerpoint, video, poster presentation, etc.)

Presentation Guidelines  Explanation of your Thermo-Can’s design and how it will work  What it is used for  Intended user of your product  A full explanation the chemical reaction you are using and calculates for the amount of reactants you need for desired temp change.  Safety and consumer warnings

Other details  Groups of 1-2  In-class work days: Friday, 5/20, Friday 5/27, and Monday 6/6  Presentations on 6/7 and 6/8  Goes in as a test grade

Larrabeans Instant, Hot Baked Beans- ON THE GO!

Design One-time use outer can (made of aluminum) Reusable inner metal can (with chili inside) Space between cans Filled with Fe3O4 powder Reaction Used: Fe 2 O Al → 2 Fe + Al 2 O 3

Instructions for use  Wet 10 square feet to prevent fire.  Place chili into re-usable metal can.  Puncture poke holes at top and run!  Food is ready within minutes.

How Larrabeans work: Steps When holes are punctured, air rushes into the can which was previously a vacuum. FeS ignites on contact with air. FeS catches the Mg on fire. Mg falls onto Fe3O4 powder and the Al can providing the starting energy for reaction which heats the food.

Uses for Larrabeans ©  Great for military use (as a fire starter and as a mobile source of warm food)  Fantastic for camping, no grill needed!  A nutritious meal that you can eat almost anywhere

Finding q  Mass of Chili = g  Change in temperature = 53°C  Specific heat of chili = 3.43 J/(g°C)  q =(m)(c)(ΔT)  q = (150.3 g)(3.43 J/(g°C))(53°C)  q =27323 Joules needed or kJ

How much reactant do we need? Fe 2 O Al → 2 Fe + Al 2 O 3 ΔH = -848 kJ/mol  Need kJ of heat from reaction  Molar mass of Fe 2 O 3 = g/mol  Molar mass of Al = g/mol kJ2 mol Al g Al 848 kJ 1 mol Al kJ1 mol Fe 2 O g Fe 2 O kJ 1 mol Fe 2 O g of Fe 2 O 3 needed1.73 g of Al needed

Safety Hazards  If the aluminum can is punctured there is a hazard for fire, skin irritation, explosion, and 3 rd degree burns.  If inner can is punctured food is unsafe to eat

Questions?  I would like to know the food you plan on using, its mass, temperature it needs to be heated to, and specific heat of your food by the end of the period.