Standard Temperature and Pressure Video Lessons

Concept: Standard Temperature and Pressure

Problem: Which gas sample has the greatest volume at STP?a) 10.0 g Arb) 10.0 g Krc) 10.0 g Xed) None of the above (They all have the same volume.)

FREE Expert Solution

Recall that standard temperature and pressure (STP) is defined as 1 atm and 0°C.

$\overline{)\mathbf{PV}\mathbf{=}\mathbf{nRT}}\phantom{\rule{0ex}{0ex}}\frac{\overline{)\mathbf{P}}\mathbf{V}}{\overline{)\mathbf{P}}}\mathbf{=}\frac{\mathbf{nRT}}{\mathbf{P}}\phantom{\rule{0ex}{0ex}}\overline{)\mathbf{V}\mathbf{=}\frac{\mathbf{nRT}}{\mathbf{P}}}$

R is constant, P and T are the same for all → compare the number of moles for each

↑ moles (n) = ↑ volume

a) 10.0 g Ar

molar mass Ar = 39.95 g/mol

moles Ar = 0.250 mol

b) 10.0 g Kr

molar mass Kr = 83.798 g/mol

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Problem Details

Which gas sample has the greatest volume at STP?
a) 10.0 g Ar
b) 10.0 g Kr
c) 10.0 g Xe
d) None of the above (They all have the same volume.)