Question

[2 Marks] A gas had a mass of 0.8396 g with a volume of 0.35 L at a pressure of 745 mm Hg and a temperature of 370 K. Calculate the molar mass.

Answer 1

74.3 g/mol

Step-by-step explanation:

PV=nRT

P=745 mmHg: (change mmHg to atm) 745/760 = 0.9803atm

v = 0.35 L

T = 370 K

rearrange the formula above: n =
`(PV)/(RT)`

plug in the info:
`((0.9803 atm)(0.35 L))/((0.08206(atm*L)/(mol*K)) (370K))` = 0.01130 mol

then take the mass / mole =
`(0.8394g)/(0.01130mol)` = 74.3 g/mol