## Essential University Physics: Volume 1 (3rd Edition)

$3 \times 10^{23}$ molecules
In order to solve this problem, we first must find how many moles there are using $PV= nRT.$ We simplify the equation and solve: $n = \frac{PV}{RT} \\ n = \frac{180,000Pa \times 8.5 \times 10^{-3} m^3}{(8.31 J/K) \times 350 K} \\ n = .53 \space mols$ Since there are $6.022 \times 10^{23}$ molecules in a mole, this means that there are $3 \times 10^{23}$ molecules.