Ask Questions, Get Answers


A flask containing 12g of a gas of relative molecular mass 120 at a pressure of 100 atm , was evacuated by means of a pump untill the pressure was 0.01 atm at the same T. Which of the following is the best estimate of the number of molecules left in the flask. $(N_0 = 6\times10^{23} mol^{-1}$)


1 Answer

At constant V and T
$\large\frac{P_1}{n_1} = \large\frac{P_2}{n_2}$
$\large\frac{100}{\large\frac{12}{120}} = \large\frac{0.01}{n_2}$
$(n_1 = \large\frac{12}{120})$
$n_2 = \large\frac{0.01}{1000}$
No. of molecules left = $6.02\times10^{23}\times10^{-5}$
Hence answer is (b)
answered Mar 5, 2014 by sharmaaparna1

Related questions