How can I solve gas problems in chemistry?

[babbagee]

I really need help on this stuff. The book that I am using right now is getting on my nerves. It is by silberberg. This book teaches everything out of order. At least that is what i think. I really need help solving the problems below.

1.)Hemoglobin is the protein that transports O₂ through the blood from the lungs to the rest of the body. In doing so, each molecule of hemoglobin combines with four molecules of O₂. If 1.00g of hemoglobin combines with 1.53mL of O₂ at 37^oC and 743torr, what is the molar mass of hemoglobin?
*I know the pressure, i know the volume, and the temp, i need moles that is the hard part.

2.) When air is inhaled, it enters the alveoli of the lungs, and varying amounts of the component gases exchange with disolved gases in the blood. As a result, the alveolar gas mixture is quite different from the atmospheric mixture. The following table presents selected data on the composition and partial pressure of four gases in the atmosphere and in the alveoli:

... are just used for spacing

Atmosphere(sea level)........Alveoli...
Gas...Mol%...PP(torr)...Mol%...PP
N₂...78.6..._____..._____...569
O₂...20.9..._____..._____...104
CO₂...0.04..._____..._____...40
H₂O...46..._____..._____...47

If the total pressure of each gas mixture is 1.00atm, calculate:
A.) The partial pressure(in torr) of each gas in the atmospehere
b.) The mol% of each gas in the alveoli
c.)the number of O₂ molecules in 0.50L of alveolar air(volume of an average breath at rest) at 37^oC
*I have no idea on how to do this.

Any help would be greatly appreciated
Thanks

 

[himanshu121]

For first which is combination of stoichiometry, and Gases state

molecular wt= 4RT/PV

 

[himanshu121]

You should remember the formulae atleast.

It would be better if u yourself relate the partial pressure with mole fraction and vice versa for the second part.

I believe formulae will lead you to the desired conclusions
And PLS show your try so that we could help u better

KEEP TRYING TILL U REACH ONE TENTH OF PROBLEM, THIS HELPS IN INCREASING ANALYTIC SKILLS