A 5.0x10^-3 m^3 container holds 4.90 g gas when the pressure is 75.0 cm Hg and the temperature is 50.0 degrees C. What will be the pressure if 6.00 g of this gas is confined to a 2.0x10^-3 m^3 container at 0.0 degrees C?

Question

Do I simply need to use the combined gas law or does the fact that they gave the masses change the rules? Thank you very much!!

Answer 1

the mass is proportional to the number of mols n2/n1 = m2/m1

P1 V1 = n1 R T1 so n1 = P1 V1/R T1

P2 V2 = n2 R T2 so n2 = P2 V2/R T2

n2/n1 = m2/m1 = (P2 V2/P1V1)(T1/T2)

6/4.9 = (P2*2/75*5)(323/273)
solve for P2