Answer:
Mg
Explanation:
Mg + Cu2+ — Mg2+ + Cu
Magnesium is oxidized because its oxidation state increased from 0 to +2 while Cu is reduced because its oxidation state decreased from +2 to 0.
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
<em>Consider the following reactions.
</em>
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
the oxidation state of copper is changed from +2 to +1 so copper get reduced.
CO + H₂O → CO₂ + H₂
the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.
Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O
The oxidation state of carbon on reactant side is +4. while on product side is also +4 so it neither oxidized nor reduced.
H₂S + 2NaOH → Na₂S + 2H₂O
The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.
Oxidizing agents:
Oxidizing agents oxidize the other elements and itself gets reduced.
Reducing agents:
Reducing agents reduced the other element are it self gets oxidized.
Answer:
If you mean the number of atoms in 8g of oxygen, it's 3.011 x 10^23 atoms.
Explanation:
Convert the grams to moles. 8 grams of oxygen is 0.5 moles. Then multiply the number of moles by Avogadro's number: 6.022 x 10^23.
The element used in advertising signs is neon.
Answer:
.
Explanation:
Consider the oxidation state on each of the element:
Left-hand side:
- O: -2 (as in most compounds);
- Cr:
; - Fe: +2 (from the charge of the ion);
Right-hand side:
Change in oxidation state:
- Each Cr atom: decreases by 3 (reduction).
- Each Fe atom: increases by 1 (oxidation).
Changes in oxidation states shall balance each other in redox reactions. Thus, for each Cr atom on the left-hand side, there need to be three Fe atoms.
Assume that the coefficient of the most complex species 
is 1. There will be two Cr atoms and hence six Fe atoms on the left-hand side. Additionally, there are going to be seven O atoms.
Atoms are conserved in chemical reactions. As a result, the right-hand side of this equation will contain
- two Cr atoms,
- six Fe atoms, and
- seven O atoms.
O atoms seldom appear among the products in acidic environments; they rapidly combine with 
ions to produce water 
. Seven O atoms will make seven water molecules. That's fourteen H atoms and hence fourteen ions on the product side of this equation. Hence the balanced equation. Double check to ensure that the charges on the ions also balance.
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