Cmc chapter 15.Chapter Menu Energy and Chemical Change Section 15.1 Energy Section 15.2 Heat Section 15.3 Thermochemical Equations Section 15.4 Calculating Enthalpy Change Section 15.5 Reaction Spontaneity Exit Click a hyperlink or folder tab to view the corresponding slides.Section 15-1 Section 15.1 Energy Define energy. Temperature: a measure of the average kinetic energy of the particles in a sample of matter Distinguish between potential and kinetic energy. Relate chemical potential energy to the heat lost or gained in chemical reactions.
Calculate the amount of heat absorbed or released by a substance as its temperature changes.Section 15-1 Section 15.1 Energy (cont.) energy law of conservation of energy chemical potential energy heat calorie joule specific heat Energy can change form and flow, but it is always conserved.Section 15-1 The Nature of Energy Energy is the ability to do work or produce heat. Two forms of energy exist, potential and kinetic. Potential energy is due to composition or position.
Kinetic energy is energy of motion.Section 15-1 The Nature of Energy (cont.) The law of conservation of energy states that in any chemical reaction or physical process, energy can be converted from one form to another, but it is neither created nor destroyed—also known as the first law of thermodynamics.Section 15-1 The Nature of Energy (cont.) Chemical potential energy is energy stored in a substance because of its composition. Chemical potential energy is important in chemical reactions. Heat is energy that is in the process of flowing from a warmer object to a cooler object.
Define chemical change and list several. During a physical or chemical change, the total amount of energy before. Properties and Changes. Energy and Chemical Change - Birdville Independent School. Chapter 16 energy chemical change assessment answer key Chapter 16 Energy Chemical Change Assessment Answer Key by Penguin Random House Chapter 16 Energy Chemical Change The energy stored In a substance because of its composition is released or obsorbed as heat during a chemical reactions or processes. A form of energy that flows from warm to cold.
Q is used to symbolize heat.Section 15-1 Measuring Heat A calorie is defined as the amount of energy required to raise the temperature of one gram of water one degree Celsius. Food is measured in Calories, or 1000 calories (kilocalorie). A joule is the SI unit of heat and energy, equivalent to 0.2390 calories.Section 15-1 Measuring Heat (cont.).Section 15-1 Specific Heat The specific heat of any substance is the amount of heat required to raise one gram of that substance one degree Celsius. Some objects require more heat than others to raise their temperature.Section 15-1 Specific Heat (cont.) Calculating heat absorbed and released q = c × m × Δ T q = heat absorbed or released c = specific heat of substance m = mass of substance in grams ΔT = change in temperature in Celsius.A B C D Section 15-1 Section 15.1 Assessment The heat required to raise one gram of a substance by one degree Celsius is called.
Specific heat D. Energy.A B C D Section 15-1 Section 15.1 Assessment Which of the following is an example of chemical potential energy? The moon orbiting Earth B. A car battery C.
A compressed spring D. A roller coaster at the top of a hill.End of Section 15-1.Section 15-2 Section 15.2 Heat Describe how a calorimeter is used to measure energy that is absorbed or released.
Pressure: force applied per unit area Explain the meaning of enthalpy and enthalpy change in chemical reactions and processes.Section 15-2 Section 15.2 Heat (cont.) calorimeter thermochemistry system surroundings The enthalpy change for a reaction is the enthalpy of the products minus the enthalpy of the reactants. Universe enthalpy enthalpy (heat) of reaction.Section 15-2 Calorimetry A calorimeter is an insulated device used for measuring the amount of heat absorbed or released in a chemical reaction or physical process.Section 15-2 Chemical Energy and the Universe Thermochemistry is the study of heat changes that accompany chemical reactions and phase changes. The system is the specific part of the universe that contains the reaction or process you wish to study.Section 15-2 Chemical Energy and the Universe (cont.) The surroundings are everything else other than the system in the universe. The universe is defined as the system plus the surroundings.Section 15-2 Chemical Energy and the Universe (cont.) Chemists are interested in changes in energy during reactions. Enthalpy is the heat content of a system at constant pressure. Enthalpy (heat) of reaction is the change in enthalpy during a reaction symbolized as Δ H rxn. Δ H rxn = H final – H initial Δ H rxn = H products – H reactants.Section 15-2 Chemical Energy and the Universe (cont.) Enthalpy changes for exothermic reactions are always negative.
Enthalpy changes for endothermic reactions are always positive.Section 15-2 Chemical Energy and the Universe (cont.).Section 15-2 Chemical Energy and the Universe (cont.).A B C D Section 15-2 Section 15.2 Assessment In thermochemistry, the specific part of the universe you are studying is called. Surroundings.A B C D Section 15-2 Section 15.2 Assessment What is the heat content of a system at constant pressure called? Heat of reaction B. Heat of the system C. Entropy.End of Section 15-2.Section 15-3 Section 15.3 Thermochemical Equations Write thermochemical equations for chemical reactions and other processes. Combustion reaction: a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light Describe how energy is lost or gained during changes of state.
Calculate the heat absorbed or released in a chemical reaction.Section 15-3 Section 15.3 Thermochemical Equations (cont.) thermochemical equation enthalpy (heat) of combustion molar enthalpy (heat) of vaporization molar enthalpy (heat) of fusion Thermochemical equations express the amount of heat released or absorbed by chemical reactions.Section 15-3 Writing Thermochemical Equations A thermochemical equation is a balanced chemical equation that includes the physical states of all reactants and products, and energy change. The enthalpy (heat) of combustion of a substance is the enthalpy change for the complete burning of one mole of the substance.Section 15-3 Writing Thermochemical Equations (cont.).Section 15-3 Changes of State Molar enthalpy (heat) of vaporization refers to the heat required to vaporize one mole of a liquid substance. Molar enthalpy (heat) of fusion is the amount of heat required to melt one mole of a solid substance.Section 15-3 Changes of State (cont.).Section 15-3 Changes of State (cont.).Section 15-3 Combustion Reactions Combustion is the reaction of a fuel with oxygen.
Food is the fuel in combustion reactions in biological systems.A B C D Section 15-3 Section 15.3 Assessment The amount of energy required to melt one mole of a solid is called. Molar enthalpy of vaporization B. Molar enthalpy of melting C.
Molar enthalpy of fusion D. Molar enthalpy of condensation.A B C D Section 15-3 Section 15.3 Assessment A thermochemical equation specifies about changes in. Temperature B. Molar mass.End of Section 15-3.Section 15-4 Section 15.4 Calculating Enthalpy Change Apply Hess’s law to calculate the enthalpy change for a reaction. Allotrope: one of two or more forms of an element with different structures and properties when they are in the same state Explain the basis for the table of standard enthalpies of formation.