If 10 raise to power 21 molecules are removed from 200 mg of CO2,then how many moles of CO2 are left?(Old and urgently dear experts)

1 Answer
Sep 26, 2016

#"Molar mass of "CO_2"=44g/"mol"#

#"Amount of "CO_2 " taken"=200mg=(0.2g)/(44g/"mol")#
#=4.55xx10^-3mol#

#"Number of mlecules of "CO_2" removed"=10^21#

#"1 mol = "6.023xx10^23 "molecules of "CO_2#

#10^21" molecules "=10^21/(6.023xx10^23)mol#

#=1.66xx10^-3mol#

#CO_2" left"=(4.55-1.66)xx10^-3mol#
#=2.89xx10^-3mol#