Avoltaic cell that uses the reaction tl3+(aq)+2cr2+(aq)→tl+(aq)+2cr3+(aq) has a measured standard cell potential of +1.19 v. write the two half cell reactio

The given net reaction is:

Tl³⁺(aq) + 2Cr²⁺ (aq) → Tl⁺(aq) + 2Cr³⁺(aq)

The half cell reaction are:

Anode(Oxidation): Involves loss of electrons

Cr²⁺(aq) ↔ Cr³⁺(aq) + e⁻  (1)

Cathode(reduction) : Involves gain of electrons

Tl³⁺ (aq) + 2e⁻ ↔ Tl⁺ (aq) (2)

The net equation can be obtained by:  2* eq(1) + eq(2)

Cr²⁺(aq) ↔ Cr³⁺(aq) + e⁻  (1)*2

 2Cr²⁺(aq) ↔ 2Cr³⁺(aq) + 2e⁻

Tl³⁺ (aq) + 2e⁻ ↔ Tl⁺ (aq) --

Tl³⁺(aq) + 2Cr²⁺ (aq) → Tl⁺(aq) + 2Cr³⁺(aq)

 A physical change in a substance doesn't change what the substance is. While a chemical change is where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.