Is disbelieving a word?
adjective incredulous, doubting, sceptical, doubtful, suspicious, dubious, unconvinced, distrustful, mistrustful, unbelieving `Is that so?’ he asked, in a disbelieving tone.
What is utter disbelief?
The word ‘Utter Disbelief’ means something which cannot be believed. It refers to something which is so unreal to be true.
What is the meaning of the word impossible?
1a : incapable of being or of occurring. b : felt to be incapable of being done, attained, or fulfilled : insuperably difficult an impossible deadline. 2a : extremely undesirable : unacceptable. b : extremely awkward or difficult to deal with the actor was impossible on the set.
What things are impossible?
Top Ten Things That Are Impossible to Do
- Lick Your Own Elbow.
- Read With Your Eyes Shut.
- Travel at Light Speed.
- Stand on Your Palms and Race Against Usain Bolt on Feet.
- Run a Two Minute Mile.
- Stand at the Checkout in a Supermarket Without Looking at What The Person in Front Has in Their Trolley.
What are some things that are irreversible?
Examples of irreversible changes
- Burning: When we burn a piece of paper or wood, it turns to ash and smoke. We cannot obtain paper and wood from the ash again.
- Cooking: We use heat for cooking, right? Once we cook our eggs, we cannot uncook them.
- Rusting of iron: You must have seen rusting of iron.
What is the difference between reversible and irreversible?
Summary. A reversible process is one in which both the system and its environment can return to exactly the states they were in by following the reverse path. An irreversible process is one in which the system and its environment cannot return together to exactly the states that they were in.
Why all natural processes are irreversible?
A process is said to be irreversible if after the process has been completed in the forward and reverse orders, the system fails to return into the initial state. It is a matter of general experience that all natural spontaneous processes are irreversible, and no natural reversible processes exist.
Are all natural processes spontaneous?
All the decay processes occur spontaneously, but the rates at which different isotopes decay vary widely.
Why is free expansion irreversible?
Since the system is isolated from the surroundings during the free expansion of the system, the surroundings does not partake in that process. Thus there is a positive total entropy change of the universe (system + surroundings) making the entire process irreversible.
Is free expansion spontaneous?
First assume that free expansion is a reversible process, means it can spontaneously happen in reverse. Free expansion is considered irreversible, as if it were reversible, it would violate Kelvin Planck statement of 2nd law. We can prove this by the following exercise.
Is adiabatic expansion reversible?
Adiabatic free expansion of a gas For an ideal gas, the temperature remains constant because the internal energy only depends on temperature in that case. Since at constant temperature, the entropy is proportional to the volume, the entropy increases in this case, therefore this process is irreversible.
What is true for free expansion process?
In free expansion there is no work done as there is no external external pressure. That’s certainly true, in fact free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber, you can think of it like ann container with a piston and the gas is left to expand in vacuum.
Is isothermal irreversible?
The isothermal compression of the gas was performed in two ways, one irreversible and one reversible. The work done on the gas is positive because the gas is compressed; the surroundings do positive work on the gas. So the heat added to the compressed gas is negative, keeping the temperature constant.
Is isothermal process always reversible?
A reversible process in which energy is exchanged via heat between a finite system and an infinite reservoir must be isothermal. Crucially, this heat exchange occurs when the system is in contact with a reservoir at the same temperature, so the entire process is reversible.
Is compression positive or negative work?
Positive work is done on the gas when the gas is compressed; negative work is done on the gas when the gas expands. zero work is done on the gas when the gas volume is fixed.