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Thermodynamics and Statistical Mechanics
Thermodynamics is the study of energy conversion between heat and mechanical work which leads to the macroscopic properties such as temperature, volume, and pressure. Statistical mechanics is the application of probability theory to study the thermodynamic behavior of systems of a large number of particles.
1,125 Questions
How do you know the third law of thermodynamics is true?
The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero is zero. This is true because of the reverse application that it is impossible to reduce any system to absolute zero in a finite number of finite operations.
To be honest, it comes from a need to define what we mean by "zero entropy". The assumption is that the alignment of a perfect crystal leaves no ambiguity as to the position of the components of the system and the orientation of each part of the crystal is identical. As the energy of the crystal is reduced, the unique vibrations of each atom are reduced to nothing. At that point all parts of the crystal are exactly the same in terms of orientations, locations, etc.
Keep in mind that with the development of quantum thermodynamics, the third law moved from a "fundamental law" to a "derived law", i.e. derived from even more fundamental laws. In this case, it comes from the definition of absolute entropy as the deviation from a state called So where everything is in one state. The deviations are counted as the number of different microstates (Ω) and the entropy is the Boltzman constant (kB) times the natural log of the microstates
S-So = kB ln Ω
It is true because that's how we define things and we have no other way of describing a situation with less entropy than a crystal that is perfectly uniform and not vibrating.
As gas particles bounce around and collide they spread to what?
As gas particles bounce around and collide, they spread to fill the available space of their container. This is because gas particles have high kinetic energy and move freely in all directions due to their random motion.
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. Many poor people in developing countries rely on vegetarian diets due to limited access to affordable protein sources like meat. Vegetarian diets can also be more sustainable and cost-effective compared to meat-based diets.
What mediums can heat travel through?
Heat can move in three ways: conduction, convection, and radiation.
In conduction, physical contact between two surfaces is required. The molecules of the heat source bang into the molecules of the heat sink, imparting some of their energy in the process, thus reducing the temperature of the heat source while increasing that of the heat sink. Heat can move by conduction through pretty much any mass, whether solid, liquid, gas, supercritical fluid, or plasma.
In convection, a substance is heated by the heat source and then moved to another location where it can release some of its energy as heat. In the case of natural convection, the motion is a result of buoyancy forces, while in forced convection something like a fan or pump is responsible for moving the heated mass. For heat to travel in this manner the medium must be capable of movement - which generally excludes solids but includes gases, liquids, supercritical fluids, and plasmas.
In radiation no medium is required to get the energy between the source and the sink. Heat can travel via radiation through a vacuum.
What do you call the heat released when 1 mole of a substance undergoes complete combustion?
You think probable to molar heat, expressed in J/mol.
Yes, height is an intensive physical characteristic, as it does not depend on the amount of substance present. Each individual's height is unique and does not change based on the quantity of the person.
How is the second law of thermodynamics related in ecology?
The second law of thermodynamics can be related to entropy. This means "all natural systems left to their own devices will follow a path of decline or become unorganised".
The reason this relates to ecosystems on earth is because if we do work on a system it can become more organised. Similar to if we were to do work on an object it would gain heat.
The relation to the second law is that natural systems left to their own devices cannot become more organised. Just like heat cannot flow from cold to hot naturally.
Comments: I've corrected some errors in that answer, but it's still a bit unusual and probably needs improving. For example living organisms
obviously can become more organised.
The second law is a bit tricky. Remember it applies to "closed systems". Open systems can be affected by "outside" things such as energy input.
As regards the first law of thermodynamics, that's basically the law of conservation of energy.
So, obviously, ecosystems need an energy source.
What is an example the first law of thermodynamics?
Our Bodies Convert Concetrated Energy to Useless Low-Grade Energy
Animals, plants, and humans, use energy changes to move, grow, catch food, and make more of themselves. Cellular respiration is the process by which most living things convert concentrated food energy into work and thermal energy (often called heat), just as car and truck engines convert fuel energy into work and thermal energy (still often called heat). Our bodies do this by controlling complex chemical reactions in which concentrated energy is carefully moved from higher molecular bond energy levels to lower molecular bond energies. On the way, some of the energy (not all) is captured by ATP molecules and used by our cells to do the useful things described above.
When you exercise, some of the food energy gets converted into muscle work, but most of it gets converted to what we engineers call low-grade thermal energy. That's why you get all hot and sweaty. In fact, more than 60% of the food energy is converted to body-warming sweat-making thermal energy during metabolism of food energy. That leaves only 40% to do useful work in the cells. If you also figure in the energy required to digest the food and to pump it around in blood to all the cells, the final number can be significantly less than 40%. That's about the same as many of our human-made engines.
And, as with human-made machines and devices, all of the mechanical work done by the cells also ends up as low-grade heat (thermal energy), lost to us forever. The total amount of energy hasn't changed (1st law), but we can't use it anymore (2nd Law).
The first law of thermodynamics, also known as the law of energy conservation, states that energy cannot be created or destroyed, only transferred or converted. In simpler terms, the total energy of an isolated system remains constant over time.
The change in internal energy is equal to the energy added minus the work done by the system. In this case, the change in internal energy is 35 J - 15 J = 20 J.
Reactants capable of interacting to form products in a chemical reaction must first?
Overcome an energy barrier known as the activation energy. This barrier is necessary to initiate the reaction by breaking existing bonds in the reactants. Once the activation energy is surpassed, the reactants can rearrange and form new bonds to create the products of the reaction.
What is the relationship among work and heat and energy?
Work is usually used for transfer of energy. If you transfer energy to an object, you "do work" on the object.
Heat is simply one type of energy.
Further Answer
Work (W) describes changing one form of energy into another. Heat (Q) describes energy in transit from a warmer body to a cooler body. So change in energy is the difference between work and heat.
change of energy = W - Q
What is coefficient of cubical expansivity?
The coefficient of cubical expansivity would normally be the cube of the coefficient of linear expansivity unless that coefficient is different in different directions for a material. In that case it would be the product of the linear coefficients in the different directions.
When do we say that an object is moving?
An object is said to have moved if it has changed its position from where it was previously. For example, of a ball rolls even a fraction of an inch, it is said to have moved because it is not in the same position as before.
The 2nd law of thermodynamics has three forms?
It has several forms, all of which are more or less equivalent, even though they don't seem so, at first glance. For example:
- In a closed system, entropy can never decrease.
- There are irreversible processes.
What cools a gas then turns it back in to liquid?
Most gases if they start near their liquid/gas equilibrium condition will cool and be partially condensed if adiabatically expanded. Other than that, any isobaric process that chills the gas would eventually cool it and turn it back into liquid as long as you are above the triple point and below the critical point temperature.
Is thermometer an example of zeroth law of thermodynamics?
No, a thermometer is a device used to measure temperature, not a demonstration of the zeroth law of thermodynamics. The zeroth law states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
What is the specific gravity of sodium hydroxide?
What is the pH of sodium hydroxide?
What I determined from a wide range pH paper is that the pH of a .1 M solution of sodium hydroxide was that between 11 and 12.
What does zeroth law of thermodynamics states?
Consider 2 beakers of water, in one beaker, the temperature of water is above room temperature, and the other is below room temperature. They are left on a table (they are not in contact with each other), after some time, equilibrium is reached. Both beakers of water are at the same temperature. The two beakers become in thermal equilibrium with the surroundings, thus they are in thermal equilibrium with each other, and they are at the same temperature.
I hope that it helps you...
What substance has greater average kinetic energy at 10 degree celsius?
At 10 degrees Celsius, gas molecules generally have greater average kinetic energy compared to liquid molecules. This is because gas molecules are in a higher energy state due to their increased vibrational and translational motion.
Where does rice take longest time to cook?
Rice typically takes longer to cook at high altitudes due to the lower boiling point of water. In high altitude areas, the lower atmospheric pressure means water boils at a lower temperature, requiring more time to cook rice thoroughly.
What is system in thermodynamics?
Thermodynamics is a branch of science that deals with heat, work, and the forms of energy possessed by matter. Thermodynamics is used to analyze thermodynamic processes and
thermodynamic cycles.
What is a violation of the first law of thermodynamics?
A cup of coffee cools down in a room cooler than it.
but the reverse.. A cup of coffee heating up in a room cooler that it because of heat transfer from the air satisfies the first and violates the second.
When energy is removed what does the decrease in energy causes the particles in that state to do?
When energy is removed, the decrease in energy causes the particles to slow down or cool down. This can lead to a decrease in movement and a potential change in state, such as from gas to liquid or solid.
