For a particular redox reaction, Cr is oxidized to CrO 2 − 4 and Fe 3 + is reduced to Fe 2 + . Complete and balance the equation for this reaction in basic solution. The phases are optional. balanced reaction: Cr + Fe^{3+} -> CrO_{4}^{2} + Fe^{2+} Cr + Fe 3 + ⟶ CrO 2 4 + Fe 2 +

8OH⁻ + Cr³⁺  + 3Fe³⁺ → 3Fe²⁺  +  CrO₄²⁻  +  4H₂O

is the balanced reaction

Explanation:

Cr³⁺ is oxidized to CrO₄²⁻ and Fe³⁺ is reduced to Fe²⁺

In basic medium, you complete with water where you have the highest value of oxygen. In the opposite side we add OH⁻ as many oxygens, we have.

8OH⁻ + Cr³⁺  →  CrO₄²⁻  +  4H₂O + 3e⁻

Chromium increased the oxidation state from +3 to +6. It released 3 electrons.

Fe³⁺  + 1e⁻ → Fe²⁺

Iron decreased the oxidation state from +3 to +2, so it won an electron.

We multiply the second half reaction x3, to balance the e⁻

(Fe³⁺  + 1e⁻ → Fe²⁺)x3 → 3Fe³⁺  + 3e⁻ → 3Fe²⁺

We mix the half reactions:

8OH⁻ + Cr³⁺  + 3Fe³⁺  + 3e⁻  → 3Fe²⁺  +  CrO₄²⁻  +  4H₂O + 3e⁻

We cancel the electrons, so the balance reaction is:

8OH⁻ + Cr³⁺  + 3Fe³⁺ → 3Fe²⁺  +  CrO₄²⁻  +  4H₂O

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.