Question #12566

1 Answer
Jan 4, 2018

~~2.2xx10^21" molecules"

Explanation:

At STP, a mole of a gas can occupy a volume of 22.4L. With this relationship, etaNH_3 can be derived; i.e.,
=80cancel(mLNH_3)xx(1cancel(LNH_3))/(1000cancel(mLNH_3))xx(1molNH_3)/(22.4cancel(LNH_3))
=0.003571molNH_3

To find the number of molecules, 1molNH_3-=6.02xx10^24NH_3 " molecules" is an important quantitative relationship to derive the unit desired in the problem; thus,
=0.003571cancel(molNH_3)xx(6.02xx10^23"molecules " NH_3)/(1cancel(molNH_3))
=0.0215xx10^23" molecules "NH_3
~~2.2xx10^21" molecules "NH_3