# Chemistry?

A 15.7 g sample of krypton exerts a pressure

of 100 mTorr at 50◦C. What is the volume of

the container?

Answer in units of L.

### 2 Answers

Relevance

- 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.

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