Which of the following gas has the rate of diffusion 0.88 times that of Phosphine (PH3) ?

a) NO2 b) N2O c) CH4 d) C2H2

1 Answer
Apr 1, 2018

#"b) N"_2"O"#

Explanation:

Rate of diffusion #("r")# and molar mass #("M")# are ralated as

#"r" ∝ 1/sqrt"M"#

#"r"_("PH"_3)/"r" = sqrt("M"/"M"_("PH"_3))#

#cancel("r"_("PH"_3))/(0.88 cancel("r"_("PH"_3))) = sqrt("M"/"34 g/mol")#

#1/0.88 = sqrt("M"/"34 g/mol")#

#"M" = "34 g/mol"/0.88^2 ≈ "44 g/mol"#

#underline(bb("Molecule") color(white)(......)bb("Molar mass"))#
#"NO"_2 color(white)(................)"46.0 g/mol"#
#"N"_2"O" color(white)(................)"44.0 g/mol"#
#"CH"_4 color(white)(................)"16.04 g/mol"#
#"C"_2"H"_2 color(white)(..............)"26.04 g/mol"#

#"b) N"_2"O"# is correct answer.