Question

Calculate the number of atoms in each of the following
a. `52 mol` of `He`
b. `52 u` of `He`
c. `52 g` of `He`

Answer 1

(i) Number of atoms of `"Ar" = 52 N_(A)`
(ii) Wt.of He `=52 xx 1.66 xx 10^(-24)gm`
Moles of He `= (52)/(4) xx 1.66 xx 10^(-24)`
Number of atoms of `"He" = (52 xx 1.66 xx 10^(-24))/(4) xx N_(A) = 13 "atoms"`
(iii) Moles of He `= (52)/(4) = 14"mol"`
Number of atoms of He `=13 N_(A)` .