Physics questions?

Question

1. During respiration, o2 combines with co2 and also releases energy in the form of heat. Where does this heat come from? Does it leave co2 cold? But we breath out warm co2.

2.Why do gas molecules of the same element not become solid under a little pressure? Why do they get away from each other?

3. Why do the gases stay afloat? why don't they fall on ground? Why do light gases rise up despite the presence of gravity?

Answer 1

1. Chemical binding energy put in the molecules at an earlier time. Doesn't leave things colder - but in lower energy states.

2. Because they are gas molecules.

3.They fall on other air molecules. Why doesn't the surface of the pond fall to the bottom of the pond? - because there is water underneath it. Who do light gases rise up? - because the heavier gases displace them underneath. Why do the raisins end up on the bottom of the raisin bran?

Answer 2

O2 does not combine with CO2. It combines with nutrients, such as carbohydrates, and release CO2, water and energy (heat). The heat comes from our body.

Gases which ar dense stay close to the Earth whereas lighter gases(hydrogen) stay afloat as the denser gases close to the ground exert a pressure upward and the gases higher up in the atmosphere can't exert a pressure greater than the gases below.[It is the reason it is less dense]
To explain it more simply, the same reason why ballons float in air.

Answer 3

I think you are a little off base here. Respiration is a broad term but I think you mean physiology respiration. Oxygen doesn't combine with carbon dioxide, they pass each other going in opposite directions. The air we breathe out is warm because we are warm, 98.6 degrees to be specific. That heat comes from cellular respiration which is a process where sugar is burned to convert ADP to ATP (which is a difference of one phosphate atom) within the mitochondria. The energy of that bond is release by the cell to do work.

All liquids and gasses become less dense under pressure. There is a law called the ideal gas law which explains this. If you take water and reduce the pressure to nearly zero, it will boil regardless of the temperature. The lower the pressure, the lower the temperature at which the water will boil. This is simple to understand. Pressure pushed atoms together, a lack of pressure allows them to expand apart. A consistent density is what the atoms are going for.

Gravity is why gasses are layered in the atmosphere the way they are. Dense gases remain low to the earth while sparse gases float higher in the air. It's the same reason oil floats on water even though both are liquids.

Answer 4

O2 does not combine with CO2. It combines with nutrients, such as carbohydrates, and release CO2, water and energy (heat). That heat comes from the energy released by the reaction itself (which is called enthalpy change of combustion).

Answer 5

O2 doesnt combine with CO2.
CO2 in our body is formed by :-

when we take our food it ge burned in our cells and energy, CO2 and water are formed. When we tak in O2 the CO2 formed in our body comes out.