Question

Of all the oxygen carried in your blood, only 2% is dierectly dissolved in your blood, while the rest is carried by a protein called hemoglobin. If human body temperature were 45° C instead of 37° C, would you expect to find more or less oxygen directly dissolved in the blood ( ignore the amount of oxygen bound to hemoglobin)? Explain using what you know of gas solubility and the way that temperture affects gas solubility. Also describe the major intermolecular force of attraction that exists between O2 and water (which makes up most of human blood).

Answer 1

Ans. #a. Solubility of gas in a liquid decrease with increase in temperature. Increase in temperature increases the kinetic energy of both the gas and solvent molecules. So, the interaction between the two decreases leading to easy escape of the gas from the liquid phase- it reduces the solubility of gas.

Therefore, if body temperature were 45.0⁰C instead of 37.0⁰C, less oxygen would directly be dissolved in blood.

#b. H2O is a polar molecule. O₂ is non-polar because two identical atoms are bonded in it.

When in contact with water molecules, there is development of induced dipole on the O₂ molecule. Thus, H₂O and O₂ are attracted through dipole- induced dipole interactions.   

The O₂ molecules also interacts with H2O molecules through London dispersion forces. It is the weakest intermolecular interactions.

# Therefore, dipole- induced dipole interaction is the major intermolecular force that is responsible for O₂ solubility in water.