Balanced Chemical Equation – Solution
2Na2S2O3 + I2 → 2NaI + Na2S4O6
The coefficients show the number of particles (atoms or molecules), and the indices show the number of atoms that make up the molecule. New substances are formed as a result of the rearrangement of the original atoms. As a result of a chemical reaction, atoms of chemical elements do not disappear anywhere and new ones do not appear, their number remains unchanged – this follows from the law of conservation of mass of substances.
Chemical Reaction Information
Sodium Thiosulfate + Diiodine = Sodium Iodide + Sodium Tetrathionate
This is an oxidation-reduction (redox) reaction. Na2S2O3 is a reducing agent, I2 is an oxidizing agent.
- 4 SII – 2 e– → 4 S5/2 (oxidation)
- 2 I0 + 2 e– → 2 I-I (reduction)
Reaction Type
Double Displacement (Metathesis)
Substances that react are called starting materials or reactants. The substances that form as a result are called reaction products.
Reactants:
Na2S2O3
- Names: Sodium thiosulfate.
- Appearance: White crystals.
I2
- Names: Iodine.
- Appearance: Bluish black or dark purple crystals with pungent odour.
Products:
NaI
- Names: Sodium iodide.
- Appearance: White solid | deliquescent.
Na2S4O6
- Names: Sodium tetrathionate.
| I2 + Na2S2O3 → NaI + NaS4O6 |
| I2 + Na2S2O3 → NaI + Na2S4O6 |
| H2O + I2 + Na2S2O3 → HI + NaHSO4 |
| NaOH + I2 + Na2S2O3 → H2O + Na2SO4 + NaI |
| I2 + Na2S2O3 → Na2S4O6 + NaI2 |
