15 Facts on H2SO4 + NaOCl: What, How To Balance & FAQs

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The chemical reactions involved in bleaching are a major concern as per the changing environmental area. Let us discuss the chemical reactivity of H2SO4 and NaOCl.

The oxidation reaction between H2SO4 and NaOCl is assessed to work as bleach and rectify the discoloration of teeth. NaOCl itself functions as a bleaching agent as it can easily be divided into oxygen and chlorine species.

The reactivity of H2SO4 and NaOCl was investigated to evaluate their bleaching potential in the case of root canal process. Moreover, the reactants can be further investigated for other chemical reactivities as explored here.

What is the product of H2SO4 and NaOCl?

The aqueous solution of sodium sulphate and hypochlorous acid is formed when sulphuric acid reacts with sodium hypochlorite.

H2SO4 + 2NaOCl = Na2SO4 + 2HClO

What type of reaction is H2SO4 + NaOCl?

H2SO4 + NaOCl is a substitution reaction where components of each compound get substituted by another component.

How to balance H2SO4 + NaOCl?

We can balance the reaction

H2SO4 + 2NaOCl = Na2SO4 + 2HClO as per the following algebraic method,

  • Each reactant and product in the equation is labeled with a variable (A, B, C, and D) to represent unknown coefficients.
  • A H2SO4 + B NaOCl = C HClO + D Na2SO4
  • Now, the equation is solved by an appropriate number, considered to be the coefficient of reactants and products.
  • H = 2A = C, S = A = D, O = 4A + 4B = C +4D, Na = B = 2D, Cl = B = C
  • All the variables and coefficients are calculated by the Gauss elimination method, and lastly, we get
  • A = 1, B = 2, C = 2, and D = 1
  • So, the overall balanced equation is,
  • H2SO4 + 2NaOCl = Na2SO4 + 2HClO

H2SO4 + NaOCl titration

H2SO4 + NaOCl reaction titration system above is an example of volumetric redox titration. We hereby discuss the apparatus and chemicals involved, conditions, and experimental procedures required for the titration.

Apparatus used

Burette, clamps, pipette, volumetric flask, conical flask, dropper, and beakers.

Indicator

Starch is the specific indicator used in the titration of H2SO4 and NaOCl.

Procedure

  • The standard solution of potassium iodate is prepared in a volumetric flask by mixing the dry crystals in deionized water.
  • Similarly aqueous solution of sodium thiosulphate is also prepared with deionized water.
  • Then burette is filled with sodium thiosulphate solution
  • Standard potassium iodate solution is pipetted in a conical flask.
  • On adding sulphuric acid and potassium iodide to the flask, the color of the solution appears to be yellowish orange.
  • At this point, sodium thiosulphate solution from the burette is added to the potassium iodate solution in the flask.
  • The color hereon starts to fade which after sometimes becomes straw-colored.
  • Starch is added to the conical flask which turns the solution into deep blue color.
  • Continuous addition of sodium thiosulphate solution dropwise to the conical flask changes the solution colorless.
  • The titration is repeated in triplicates for concordant readings.
  • We achieve a standard concentration of aqueous thiosulphate solution for further titration of the bleach.
  • Commercial bleach is diluted by mixing with deionized water in a volumetric flask.
  • Now, excess acidified potassium iodide solution is added to the hypochlorite solution.
  • Then sodium thiosulphate from the burette is titrated to the bleach solution in the conical flask until the brown color changes to yellow.
  • Few drops of indicator, starch is added to the conical flask which forms a complex with iodine and turns the solution deep blue.
  • Again, sodium thiosulphate is added dropwise to the conical flask to turn the solution colorless.
  • The titration process is repeated in triplicate to achieve concordant readings.
  • The concentration of hypochlorite in the original undiluted bleach is thus calculated as.
  • C (undilute) = {C (dilute) * V (dilute)} / V (undilute)

Where C and V are the concentration and volume of respective diluted and undiluted bleach solutions.

H2SO4 + NaOCl net ionic equation

The net ionic equation of H2SO4 + NaOCl is,

H+ (aq) + ClO– (aq) = Cl– (aq) + H2O (l)

The following steps are used to derive the net ionic equation:

  • Firstly, write the balanced chemical equation and represent the physical states of reactants and products
  • H2SO4 (aq) + 2NaOCl (aq) = Na2SO4 (aq) + 2HClO (aq)
  • Now, strong acids, bases and salts dissociate into ions whereas pure solid substances and molecules do not dissociate
  • H+ (aq) + ClO– (aq) = Cl– (aq) + H2O (l)

H2SO4 + NaOCl conjugate pairs

H2SO4 + NaOCl can exist as conjugate pairs,

  • Conjugate pair of H2SO4 = HSO4–
  • Conjugate pair of NaOCl = ClO‑

H2SO4 and NaOCl intermolecular forces

H2SO4 + NaOCl reaction has the following intermolecular forces,

  • Strong hydrogen bonding, van der Waals dispersion forces, and dipole-dipole interactions exist between the molecules of H2SO4.
  • Polar dipole forces exist between NaOCl molecules.

H2SO4 + NaOCl reaction enthalpy

H2SO4 + NaOCl is found to report no reaction enthalpy in the literature search due to stochiometric properties.

Is H2SO4 + NaOCl a buffer solution?

H2SO4 + NaOCl reaction do not form a buffer solution as strong acids do not form a buffer.

Is H2SO4 + NaOCl a complete reaction?

H2SO4 + NaOCl is a complete reaction as stable products are formed as products.

Is H2SO4 + NaOCl an exothermic or endothermic reaction?

H2SO4 + NaOCl is considered to be an exothermic reaction because the addition of sulphuric acid will lead to the liberation of heat.

Is H2SO4 + NaOCl a redox reaction?

H2SO4 + NaOCl do not show a redox reaction because only oxidation of NaOCl takes place in this reaction.

Is H2SO4 + NaOCl a precipitation reaction?

H2SO4 + NaOCl is not a precipitation reaction, as no precipitates are observed at the end of the reactions.

Is H2SO4 + NaOCl reversible or irreversible reaction?

H2SO4 + NaOCl is irreversible because the formed products cannot convert back into the original reactants.

Is H2SO4 + NaOCl displacement reaction?

H2SO4 + NaOCl is a displacement reaction as a double displacement of molecules from the reactants is observed.

Conclusions

The reaction of sulphuric acid with sodium hypochlorite is an example of an oxidation reaction where bleaching occurs with the oxidizing power of commercial bleach. It acts by oxidizing the stain molecules to fade the color of these molecules. Hypochlorite solutions cause white spots on clothes and can also irritate eyes and skin.