Question

A chemist pours 1 mol of zinc granules into one beaker and 1 mol of zinc chloride powder into another beaker. What do the two samples have in common?

Answer 1

Beaker-1 has same number of zinc atoms as that of the zinc ions in beaker-2.

Step-by-step explanation:

In beaker-1 , we have added 1 mol of zinc granules.

1 mol =
`6.022* 10^(23)` atoms

In beaker-1
`6.022* 10^(23)` atoms of zinc are present.

In beaker-2, we have added 1 mole of zinc chloride.

`ZnCl_2(aq)\rightarrow Zn^(2+)(aq)+2Cl^-(aq)`

1 mole of zinc chloride gives 1 mole of zinc chloride gives one mole of zinc ions and 2 moles of chloride ions.

1 mol of Zinc ion =
`6.022* 10^(23)` ions

The both samples have:

`6.022* 10^(23)` zinc atoms =
`6.022* 10^(23)` zinc ions

Beaker-1 has same number of zinc atoms as that of the zinc ions in beaker-2.

Answer 2

Answer is: two samples have in common same amount of substance and same number of particles.
1) There are same amount of substance in both beakers:
n(Zn) = 1 mol.
n(ZnCl₂) = 1 mol.
2) There are same number of particles (atoms, molecules, ions) in both beakers:
N(Zn) = n(Zn) · Na.
N(Zn) = 1 mol · 6.023·10²³ 1/mol = 6.023·10²³ atoms of zinc.
N(ZnCl₂) = n(ZnCl₂) · Na.
N(ZnCl₂) = 1 mol · 6.023·10²³ 1/mol = 6.023·10²³ molecules of zinc(II) chloride.
Na - Avogadro number.