 Respond to at least One question below using the organizer provided. Be prepared to share your thoughts  QUESTIONS:  1. Describe what happens to a rat that has been eaten by a python.  2. What is the function of the digestive system? What are calories?  3.How can you measure the calories contained in food?  4. What do you think happens if a person eats more calories than their body needs?

ce/nvsn6.sci.bio.fuel/food-is-fuel/

 define the terms system and surroundings in the context of a chemical reaction.  identify the system and surroundings in a thermochemical reaction.  describe how heat is transferred in endothermic and exothermic reactions  Calculate specific heat of a substance in calories and joules  Calculate enthalpy changes in a thermochemical rtn  Apply Hess’s law of heat summation in a thermochemical equation.

 TERMINOLOGIES:  Thermochemistry: studies energy changes in chemical reactions and changes of state.  Heat (q): is the transfer of energy from one object to another because of temperature difference (warmer to cooler object)  System: part of the universe being studied or focus of attention (e.g. reactants and products of a reaction)  Surroundings: the immediate vicinity of the system (e.g. container, space, universe, e.t.c.)  Law of conservation of energy: states that energy is neither created nor destroyed in any chemical or physical process.

 COMPARE AND CONTRAST USING VENN DIAGRAM  Exothermic Process: o Heat is release to the surroundings (surroundings warms up) o The system loses heat (system products cools down) o q= negative  Endothermic Process: o Heat is absorbed from the surroundings (surroundings cool down) o The system gains heat (system products warms up) o q= positive

 Calorie (cal) : quantity of heat needed to raise the temperature of 1g of pure water to 1 0 C. o 1 Calorie = 1 Kilocalorie = 1000 calories o 20 Cal (dietary potential energy) = 20 Kcal (when energy completely used up/released)  Joules (S.I. Unit of energy) o One Joule (1J) of heat is the energy needed to raise the temperature of 1g of pure water to C o Unit Conversion: o 1J = cal 4.184J = 1cal o 1000J = 1kJ (kiloJoules)

 Heat Capacity: amount of heat needed to increase the temperature of an object to exactly 1 0 C. ( Unit for heat capacity = J/ 0 C)  Heat capacity depends on: o Mass of an object o Chemical composition of the object  Specific Heat Capacity (C): is the amount of heat it takes to raise the temperature of 1g of substance (object) to 1 0 C. (Unit for Specific Heat = J/(g. 0 C) or J/(kg. 0 C) or kcal/(kg. 0 C) ). Remember: 1000g = 1Kg

 Thumbs Up  Thumbs Down  Thumbs side  What is your level of understanding on: o System and surroundings o Endothermic and Exothermic o Calorie/Kilocalorie o Heat Capacity o Specific Heat Capacity

Formula for calculating Specific Heat Unit for Specific Heat Specific Heats of some common substances (see PHC: table 17.1, page 508)

 When 435J of heat is added to 3.4g of olive oil at 21 0 C, the temperature increases to 85 0 C. What is the specific heat of the olive oil?  How much heat is required to raise the temperature of 250.0g of mercury 52 0 C?  An orange contains 445kJ of energy. What mass of water could the same amount of energy raise from C to the boiling point?