Step 1: A scuba tank is filled to a pressure of about 21,000 kPa at 295K. The volume of the tank is 25 L. Find the number of moles of air in the tank.
Step 2: The molar mass of air is about 29 g. Determine the mass of air in the tank (Use your answer from Step 1 above). If 1 kg = 2.2 lbs, how much does the air weigh?
2007-05-06 21:24:54 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Using universal gas eqn.
PV = nRT
n = PV/RT
here,
n= 21000*10³ * 25*10^(-3) / (295 * 8.314) = 214.056 moles
2) mass of the contained gas = 214.056 * 29 g = 6207.622 g
= 6.207622 kg = 6.207622 * 2.2 lbs = 13.6568 lbs
2007-05-06 23:16:10 · answer #1 · answered by s0u1 reaver 5 · 0⤊ 0⤋
step 1
pV =nRT
n= pV/RT p= 21000kPa= 2.1*10^7Pa v= 25L =0.025m^3
So n= 2.1 10^7*0.025/(8.31*295) =214.1 moles
step 2 mass of the air = 29 10^-3 *214.1 =6.21 kg =13.66lbs
2007-05-07 05:09:51 · answer #2 · answered by maussy 7 · 0⤊ 0⤋