Answer:
2.08×10^24 atoms
Explanation:
set up a mole to atom ratio:
3.47moles 1 mole
------------------ = ----------------------------
x atoms 6.02×10^23 atoms
cross multiply:
3.47 mole × 6.02 × 10^23 = 2.08×10^24 atoms
<h3>Zinc +oxygen - zinc oxide</h3>
<h3><em>chlorine</em><em>+</em><em> </em><em>magnesium</em><em> </em><em>-</em><em> </em><em>magnesium</em><em> </em><em>dichloride</em></h3><h3><em>iron</em><em> </em><em>+</em><em> </em><em>arsenic</em><em> </em><em>-</em><em> </em><em>ferric</em><em> </em><em>arsenate</em></h3>
<h2><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em>Hope</em><em> </em><em>it</em><em> </em><em>is</em><em> </em><em>helpful</em><em> </em><em>for</em><em> </em><em>you</em></h2>
The equation is as follow,
Cr₂O₇²⁻ → Cr³⁺
Balance the Cr atoms,
Cr₂O₇²⁻ → 2 Cr³⁺
Identify Oxidation Number of Elements on Both sides,
Left Hand Side;
Cr = +6
O = -2
Right Hand Side;
Cr = +3
O = -2
Means each Cr is gaining 3 electrons to change into +3 state, Hence, 6 electrons are gained by two Cr atoms, So,
Cr₂O₇²⁻ + 6e⁻ → 2 Cr³⁺
Balance Oxygen atoms, as it is acidic medium, add H⁺ ion on the side containing large number of Oxygen atoms and H₂O on side containing less number of Oxygen atoms, So,
H⁺ + Cr₂O₇²⁻ + 6e⁻ → 2 Cr³⁺ + H₂O
Now Balance H and O,
14 H⁺ + Cr₂O₇²⁻ + 6e⁻ → 2 Cr³⁺ + 7 H₂O
6 electrons are transferred in this reaction.