2.Topic №2: Bases of the chemical thermodynamics. Thermo-chemical equation.

Basic questions:

1. Law of conservation of energy - the main law of nature.

2. Thermodynamics and bioenergetics. The main concepts and terms of topic.

3. First law of thermodynamics. Internal energy. Enthalpy.

4.Thermo-chemical. Hess’s law. Thermo-chemical calculations.

5. Fuel value of food .

6. Standard condition and thermochemical (enthalpy of formation)

7. Second law of thermodynamics. Spontaneous and non spontaneous processes . Gibb's energy. Entropy.

8. The united law of the thermodynamics. The criteria and direction of the spontaneous processes. Enthalpy and entropy factors in spontaneous process.

9. Specific of the living organisms as the thermodynamic objects.

1)Law of conservation of energy - the main law of nature.

The law of conservation of energy, first formulated in the nineteenth century, is a law of physics. It states that the total amount of energy in an isolated system remains constant over time. The total energy is said to be conserved over time. For an isolated system, this law means that energy can change its location within the system, and that it can change form within the system, for instance chemical energy can become kinetic energy, but that energy can be neither created nor destroyed.

In the twentieth century, the definition of energy was broadened. It was found that particles that have rest mass are equivalent to amounts of energy (see mass-energy equivalence). There particles were found subject to annihilation in which matter particles (such as electrons) can be converted to non-matter (such as photons of electromagnetic radiation), or even into potential energy or kinetic energy. Matter could also be created out of kinetic or other types of energy, in the process of matter creation. Thus, matter (defined as ponderable matter particles) was found not to be conserved.

2) Thermodynamics and bioenergetics. The main concepts and terms of topic

Thermodynamics – is the study of the relationship between heat, work and energy. It is a science about interaction of different kinds of energy, direction, possibility and limits of spontaneous processes.

Thermodynamics is divided into general, chemical and technical. The object of thermodynamics investigation is a system.

Thermodynamic system - is any separate body having shape, possesses volume, having lots of particles it is a part of physical space separated from the environment by real or imaginary border. ( for example bottle with water, 1 mole of a substance containing 10 "' particles, ions, molecules etc.)

Depending on relation to environment thermodynamic systems may be divided into three types:

Open system - is a system that can exchange both matter and energy with the surroundings. Examples are ocean, sea, man.

Closed system - is a system that can exchange energy but not matter with the surroundings. Examples are radiator, central heating battery.

Isolated system - it is a system that exchange nether energy nor matter with its surroundings. Examples are calorimeter, thermos.

According to the state of matter thermodynamic systems are divided into two types:

Homogeneous is a system all parts of which have identical properties.

Examples are clean air without dust, pure water.

Heterogeneous it is a system different parts of which have different properties and there is border between them. Examples are room, man, glass with water and oil.

Each homogeneous part of heterogeneous system is called phase.

Component - is a chemical substance forming system.

Example pool in spring has only one component H₂O but three phases water gas, water liquid and water solid or ice.

Water with sugar has one phase - liquid but two components water and sacchrose.

Each thermodynamic system is described by thermodynamic parameters.

Parameters are values characterizing any property of the system.

V - volume (liter, milliliter)

P - pressure (kPa, Pa)

C - concentration (mole/1)

T - temperature (K)

Q-heat (kJ, J)

U - internal energy (kJ, J)

A - work (kJ, J)

H - enthalpy or reaction energy (kJ, J).

The main parameter is energy. All kinds of energy is measured in J, kJ or calorie, kilo-calorie.