There is still air inside of a house, which is pushing the roof upwards, so the forces are equal and the roof is not crushed.
The main reason why it's very dangerous to open compress gas tank is it can cause major disaster not only in human but also in plants and animals. Compress gas is flammable. And it's like a bomb the damage of gas tank is very catastrophic. It is very harmful if mishandled.
To solve the problem it is necessary to apply the concepts related to the conservation of energy through the heat transferred and the work done, as well as through the calculation of entropy due to heat and temperatra.
By definition we know that the change in entropy is given by
Where,
Q = Heat transfer
T = Temperature
On the other hand we know that by conserving energy the work done in a system is equal to the change in heat transferred, that is
According to the data given we have to,
PART A) The total change in entropy, would be given by the changes that exist in the source and sink, that is
On the other hand,
The total change of entropy would be,
Since the heat engine is not reversible.
PART B)
Work done by heat engine is given by
Therefore the work in the system is 100000Btu
Because Na⁺ ion lacks an electron and O²⁻ has two extra electrons extra, to balance the charge, we need 2 Na⁺ ions.
All ions, atoms and molecules want to get to the minimum energy state, and that state is when the ion, atom, or molecule is neutral, that's why all of them want to balance their charges.