A tank in a room at 19°C is initially open to the atmosphere on a day when the b

Question

A tank in a room at 19°C is initially open to the atmosphere on a day when the barometric pressure is 102 kPa. A block of dry ice (solid CO2) with a mass of 15.7 kg is dropped into the tank, which is then sealed. The reading on the tank pressure gauge initially rises very quickly, then much more slowly, eventually reaching a value of 3.27 MPa. Assume Tfinal =19°C. How many moles of air were in the tank initially? assume that a negligible amount of CO2 escapes prior to the sealing of the tank. (The specific gravity of solid carbon dioxide is approximately 1.56.)

Explanation / Answer

nCO2 = 15.7 kg = 15.7 x 1000 / 44.01 = 0.357 kmolCO2

Assume ideal gas behavior, negligible temperature change (T =19 degrees C = 292 K)

P1V / P2V = n1RT /(n1 + 0.357)RT

(n1) / (n1+ 0.357) = (P1 / P2) = [(102kPa) /(3.27x103 kPa)

n1 = 0.0115 k mol air in the tank

moles of air in tank initially = 0.0115 k mol

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.