4/12.17 - Physics Help Please! How many mols *Hard Problem*?

Question

Determine the number of moles of oxygen gas in the following containers.

A) Container A holds 0.90m^3 at 25C and an absolute pressure of 14kPa. n= ???mol

B) Container B holds 0.90m^3 at 57F and an absolute pressure of 16kPa. n= ???mol

C) Container C holds 0.30m^3 at 25C and gauge pressure of 42kPa. n= ???mol

Answer 1

Well for an ideal gas PV=nRT (ideal gas law)

P  is the absolute pressure of the gas,

V is the volume of the gas,

n is the number of moles of gas,

R is the universal gas constant, (8.314472 J·mol^−1·K^−1)

T is the absolute temperature

A)  14000 * 0.90 = n * 8.314472 * (25+273)

=> n =  5.1 mol

B) 57 F = 287 K

=> n = 6.0 mol

C) n = 5.1 mol