Physics Ideal Gas Law Problem?

Question

Hey guys, I have a problem to solve and have been doing it incorrectly.

The problem goes:

The average molecular weight of air is 28.9. Assume that air obeys the ideal-gas law, 1 atm = 101300 N/m^2, Avogadro's constant is 6.02214 x 10^23 mol^-1, and k = 1.38065 x 10^-23 Nm/K.
Estimate the number of molecules in a room (5 m) x (14 m) x (19 m) at standard pressure of 101300 N/m^2 and a standard temperature of 273 K. Answer in units of molec.

Any help would be greatly appreciated, thanks very much!

Answer 1

The easiest way is to use the formula
pV = NkT
Solve for N, the number of molecules.
N = pV/(kT)

If you want to you can start with the other form of the ideal-gas equation:
pV = nRT

Then use the formulas k = R/N_A and N = N_a * n
You can substitute these two formulas to get the first one I gave.

Answer 2

At STP, 1 mol of air has a volume of 22.4 L.
Use dimensional analysis,
(5 m) x (14 m) x (19 m) (1000L/m^3)(mol/22.4)(6.02*10^23 molecules/mol) = 3.574 x 10^28 molecules

Answer 3

suitable gas regulation equation says: PV=nRT P=rigidity ... which is going to cut back through fact the bubble is going up, through fact it is going to have much less water over it, ok? V=volume is going to alter, shall we come across how plenty n=sort of moles .. as you at the instant are not introducing greater air neither taking air out of the bubble, its going to be consistent R= suitable gas consistent T= temperature, you have already got the values you ought to use this equation interior the lowest of the lake, and interior the top area, .... backside: PV=nRT, you dont comprehend P and n, yet with the hydrostatic rigidity equation you are able to calculate it P = d*g*h d= density of the liquid (water consequently one thousand kg/m3 or 1g/cm^3) g = gravity acceleration (9.eighty one m/s^2) h = deepth you have already got P in simple terms don´t ignore to function the atmospheric rigidity, so now shall we come across n .... (pay attention or the instruments in wich you introude P and R, suitable now i dont have any R values table, yet you are able to seem for it even at wikipedia, sorry for this) now shall we pass to the top area of the lake PV=nRT P stands out as the atmospheric rigidity n is a similar you calculated at tha backside R is persevering with T already comprehend, 20C on the exterior waiting to calculate V desire i had helped, good success...... playstation ... staring on the previous answer, its an much less complicated way and you pass calculating "n", the only mistake is at including that its nos including the atmospheric rigidity in the two fringe of the ecuation