Question

# The best laboratory vacuum has a pressure of about 1.00 * 10^{-18} atm, or 1.01 *10^{-13} Pa. How many gas molecules are there per cubic centimeter in such a vacuum at 293 K?

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The best laboratory vacuum has a pressure of about $$\displaystyle{1.00}\cdot{10}^{{-{18}}}$$ atm, or $$\displaystyle{1.01}\cdot{10}^{{-{13}}}{P}{a}$$. How many gas molecules are there per cubic centimeter in such a vacuum at 293 K?
n=PV/RT where $$\displaystyle{P}={1.01}\times{10}^{{-{13}}}{P}{a},{V}={1}\times{10}^{{-{6}}}{m}^{{{3}}}$$, R = 8.31 and T = 293 K, then remember that 1 molehas $$\displaystyle{6.022}\times{10}^{{{23}}}$$ molecules