(i) Calculate the gram molecular mass of `NH_(3)`

Explanation

(i) Atomic mass of N=14
Gram molecular mass of `NH_(3)=(14xx1)+(1xx3)`
=`14+3=17 g`
(ii) `"Mass percentage"=("Mass of the solvent")/("Mass of the solute+Mass of the solvent")`
=`(500)/(500+50)xx10`
=`(500)/(550)xx100=90.90%`
(iii) Mass of water =0.18 g
`"Number of moles"=("Mass")/("Molecular Mass")`
=`(0.18)/(18)=0.01` mole
`"Number of molecules"="No. of moles"xx"Avogadro number"`
=`0.01xx6.023xx10^(23)`
=`0.06023xx10^(23)`
=`6.023xx10^(21)` molecules