# The pressure of the atmosphere is $2\times10^{-6}$ at about 100 mile above the earth and temperature is $-180^{\large\circ}C$ .How many mole are there in 1 mL gas at this altitude?

$\begin{array}{1,1}(a)\;3.46\times10^{-10}mole\\(b)\;\;3.45\times10^{-13}mole\\(c)\;\;3.45\times10^{-9}mole\\(d)\;\;3.45 mole \end {array}$

Given
$P = \large\frac{2\times10^{-6}}{760}$atm
T = -180 + 273 = 93K
V = 1 mL = $\large\frac{1}{1000}$litre
$PV = nRT$
$\large\frac{2\times10^{-6}}{760}\times10^{-3} = n\times0.0821\times93$
$n = 3.45 \times 10^{-13} mole$