Thermochemistry
Module No. 6
Energy Relationships in Chemical Reactions
The Nature of Energy and Types of Energy
Energy – is the capacity to do work or to transfer heats.
Forms of Energy 1. Kinetic energy 2. Radiant energy 3. Thermal energy 4. Chemical energy 5. Potential energy
Energy Changes in Chemical Reactions
Heat – is the transfer of thermal energy between two bodies that are at different temperature.
Thermochemistry – is the study of heat change in chemical reactions.
Terms: System – part of the universe set aside for study.
Surroundings – part of the universe outside the system
Types of systems: 1. Open system – can exchange mass and energy usually in the form of heat with its surroundings. 2. Closed system – allows transfer of energy but not mass. 3. Isolated system – does not allow the transfer of either mass or energy.
Types of energy or heat transfer
1. Exothermic process – gives off heat to its surroundings Example: 2H2(g) + O2(g) → 2H2O(l) + energy 2. Endothermic process – absorbs heat from its surroundings Example: Energy + 2HgO(s) → 2Hg(l) + O2(g)
_____________________________________________________________________________________ Practice Exercise 6.1: Tell whether the following is an open, closed or isolated system. a. tree b. steel c. rice cooker d. coleman jug e. oven f. electric fan g. automobile h. hammer
Introduction to Thermodynamics
Thermodynamics - study of the interconversion of heat and other kinds of energy.
Thermodynamic state of a system – defined by a set of condition that completely specifies all the properties of the system, such as temperature, pressure, composition (identity and amount) and physical state (gas, liquid, solid)
State Function – depends only
Energy Relationships in Chemical Reactions
The Nature of Energy and Types of Energy
Energy – is the capacity to do work or to transfer heats.
Forms of Energy 1. Kinetic energy 2. Radiant energy 3. Thermal energy 4. Chemical energy 5. Potential energy
Energy Changes in Chemical Reactions
Heat – is the transfer of thermal energy between two bodies that are at different temperature.
Thermochemistry – is the study of heat change in chemical reactions.
Terms: System – part of the universe set aside for study.
Surroundings – part of the universe outside the system
Types of systems: 1. Open system – can exchange mass and energy usually in the form of heat with its surroundings. 2. Closed system – allows transfer of energy but not mass. 3. Isolated system – does not allow the transfer of either mass or energy.
Types of energy or heat transfer
1. Exothermic process – gives off heat to its surroundings Example: 2H2(g) + O2(g) → 2H2O(l) + energy 2. Endothermic process – absorbs heat from its surroundings Example: Energy + 2HgO(s) → 2Hg(l) + O2(g)
_____________________________________________________________________________________ Practice Exercise 6.1: Tell whether the following is an open, closed or isolated system. a. tree b. steel c. rice cooker d. coleman jug e. oven f. electric fan g. automobile h. hammer
Introduction to Thermodynamics
Thermodynamics - study of the interconversion of heat and other kinds of energy.
Thermodynamic state of a system – defined by a set of condition that completely specifies all the properties of the system, such as temperature, pressure, composition (identity and amount) and physical state (gas, liquid, solid)
State Function – depends only