Question

Number of Zn atoms present in 122 g of ZnO is
(Atomic wt of Zn = 65).
(1) NA
(2) NA/2
(3) 3NA/2
(4) 2 NA​

Answer 1

Answer:

(3) 3Na/2 is correct answer

Answer 2

Answer:

Number of $Zn$ atoms present in 122g of $ZnO$ is (3/2)$N_{A}$.

Therefore the option (3) is correct.

Explanation:

Given: the atomic number of the zinc oxide  $=65+16=81gmol^{-1}$

Number of Zn atoms contain 81g of ZnO$=1 mole$

One mole of compound contains 6.623×10²³ atoms or Avogadro number of molecules ($N_{A$) .

Therefore,

Number of Zn atoms present in 81g of ZnO $=N_{A}$

$Number of Zn atoms present in 122g of ZnO$ $=\frac{122}{81} *N_{A}=1.5N_{A}$