A 15.7 g sample of krypton exerts a pressure
of 100 mTorr at 50◦C. What is the volume of
Answer in units of L.
- az_lenderLv 73 weeks ago
Atomic mass of krypton is 83.798 g/mol, so the 15.7 grams represent about 0.1874 moles.
V = nRT/p
= (0.1874)(8.314 Pa m^3)(323.15)/(13332 Pa)
= use calculator
- pisgahchemistLv 73 weeks ago
This is just a variation on the ideal gas equation ....
PV = nRT ............ ideal gas equation
PV = mRT / M...... n=m/M ... m=mass, M=molar mass
V = mRT / (MP) .. solve for volume
V = 15.7g x 62.36 Ltorr/molK x 323K / 83.8 g/mol / 0.100 torr
V = 38,000L ........ to two significant digits
We'll split the difference on precision. 15.7g has three significant digits and 100 millitorr is ambiguous, so we'll arbitrarily settle on two significant digits.