Describe briefly how a submarine may remain underwater for sifnificant lengths of time.?

Question

just how it remains underwater for a long time (explained in a chemistry way lol, like hydrogen bondings if that's got anything to do with it)

Answer 1

Nuclear submarines can stay underwater for a whole year because they dont need to refuel often. They run on mini nuclear power stations.

The means to extract oxygen out of water by running electricity through it is the best means of producing breathable air, especially as you have a huge power source.

With such a large power source the submarine can also be larger, thereby having larger cargo holds and room for more food!

A diesel submarine (more traditional type) can not stay underwater for as long as it runs out of fuel and therefore can not do as the nuclear submarine does. It is also smaller and so can not store as much food.

optimally a robotic submarine is most efficient as it needs no air or food, just power.

The formula for removing oxygen from water is :

2H2O => 2H2 + O2

Answer 2

Nuclear subs can stay submerged for a long time due to the reactor not depending on air to produce heat to operate its steam turbines.  

The oxygen generator uses electricity to split water into oxygen and hydrogen. 2H20=2H2 + O2.  Oxygen candles can also be burned in a furnace to produce oxygen.  gas.http://en.wikipedia.org/wiki/Chemical_ox...  

Scrubbers removed carbon dioxide from the air by absorbing it with amine.  Hydrocarbons and carbon monoxides are removed by burning them in a hot catalytic bed to make carbon dioxide and water.  

Water is made onboard by evaporating seawater and condensing the steam into pure water.  

Filters and precipitators remove solid airborne contaminants from the air.

Diesel subs can use air independent propulsion systems utilizing liquid oxygen or fuel cells to allow operation without drawing in outside air.  http://en.wikipedia.org/wiki/Air-indepen...

Ranb