Which has more atoms: 17.031 grams of ammonia, #NH_3#, or 72.922 grams of hydrogen chloride, #HCl#?

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Answer 1 · 2017-03-11T15:18:59

#72.922g# of #HCl#

the answer to this would be the substance that has more moles.

#n = m/M#

(number of moles = mass/molar mass)

molar mass (g/mol) = atomic mass (g/mol), which can be found on the Periodic Table on the top-left of each element symbol.

#A_r (N) = 14#
#A_r (H) = 1#
#A_r (Cl) = 35.5#

#M_r(NH_3) = (14 * 1) + (1 * 3) #
#= 14+3#
# = 17#

#M_r(HCl) = 1 + 35.5#
# = 36.5#

#NH_3#:

#n = m/M#

#=17.031/17#

#~~1# mole

#HCl#:

#n = m/M#

#=72.922/36.5#

#~~2# moles

#1# mole of atoms= #6.02 * 10^23# atoms
(Avogadro's constant)

#therefore 2# moles of atoms = #1# mole of atoms #+6.02 * 10^23# atoms

hence, there are more atoms in #72.922g# of #HCl#.