HCl and Na2S2O3 are the chemical names of hydrochloric acid and sodium thiosulfate. Here, we are discussing the chemical reaction within HCl and Na2S2O3 compounds.
Hydrochloric acid is a strong acid composed of two elements i.e. hydrogen atom and chlorine atom. Sodium thiosulphate is an inorganic salt and is composed of mainly three elements i.e. 2 sodium atoms, 2 sulfur atoms, and 3 oxygen atoms.
In this article, we learn about the balanced equation, product, intermolecular forces, titration, enthalpy, net ionic equation, and many more facts with some FAQs on HCl + Na2S2O3 chemical reaction.
What is the product of HCl and Na2S2O3?
The product of HCl + Na2S2O3 is sodium chloride (NaCl), water (H2O), sulfur dioxide gas (SO2), and sulfur (S) metal.
Na2S2O3 + 2 HCl → 2 NaCl + H2O + SO2 + S
What type of reaction is HCl + Na2S2O3?
The HCl + Na2S2O3 is a disproportionate or dismutation reaction.
How to balance HCl + Na2S2O3?
The HCl + Na2S2O3 chemical reaction is balanced with the help of the following steps:
- The unbalanced reaction of HCl + Na2S2O3 is given below:
- Na2S2O3 + HCl → NaCl + H2O + SO2 + S
- We have to multiply HCl on the left-hand side by 2, so we get.
- Na2S2O3 + 2 HCl → NaCl + H2O + SO2 + S
- Later we have to multiply Na2S2O3 on the right-hand side by 2, and we get.
- Na2S2O3 + 2 HCl → 2 NaCl + H2O + SO2 + S
HCl + Na2S2O3 titration
The HCl + Na2S2O3 reaction titration experiment is done to determine the rate of reaction by applying different concentrations of Na2S2O3 treated with HCl.
Apparatus:
- 5 – 100 ml beakers
- 2 – 50 or 100 ml Graduated cylinders.
- 5 – 10 ml Graduated cylinders
- Permanent marker
- Lightbox or overhead projector
- Timer or stopwatch
- Stirring rods
Chemicals:
- 25 ml, 2 molars, Hydrochloric acid solution
- 150 ml, 0.15 molar, Sodium thiosulfate solution.
- Deionized or distilled water
Procedure:
- Label the entire five 100 ml beakers as 1 to 5 and clean the bottom of every beaker.
- Make a large “X” at the bottom of the beaker and place it on the stage of the lightbox or projector, so the X can be visible.
- Using a separate graduated cylinder, add the 0.15M Na2S2O3 solutions in each of the five beakers as 1 – 50 ml, 2 – 40 ml, 3 – 30 ml, 4 – 20 ml, and 5 – 10 ml.
- Later add the distilled water in the same five beakers 1 – 0 ml, 2 – 10 ml, 3 – 20 ml, 4 – 30 ml, and 5 – 40 ml.
- Now, evaluate the Na2S2O3 final concentration in each beaker from 1 to 5.
- Note the values of volume of Na2S2O3 in a beaker, concentration of Na2S2O3, distilled water volume, reaction time in seconds, and 1/reaction time i.e. reaction rate.
- Take 5 ml of 2 M HCl solution in each five 10 ml graduated cylinders.
- Add the 5 ml HCl solution in each of the 5 beakers containing Na2S2O3 and distilled water solution, stir it with a stirring rod and immediately start the stopwatch.
- Stop the timer if the “X” on the beaker is not visible. Note the reaction time (sec) and repeat the same procedure with 2 to 5 beakers.
- Calculate the reaction rate for each trial and plot two separate graphs against concentration Vs reaction time and concentration Vs reaction rate.
HCl + Na2S2O3 net ionic equation
- The net ionic equation for HCl + Na2S2O3 chemical reaction is.
- 2Na+ + S2O3– + 2H+ + 2Cl– → 2Na+ + 2Cl– + H2O + SO2 + S
- Cancel the same moieties on both sides we get.
- S2O3– + 2H+ → H2O + SO2 + S
HCl + Na2S2O3 conjugate pairs
HCl + Na2S2O3 is a conjugate pair as HCl donates its proton and acts as conjugate acid, while Na2S2O3 accepts a proton and forms NaCl thus acting as a conjugate base.
HCl and Na2S2O3 intermolecular forces
The intermolecular forces shown by HCl and Na2S2O3 are,
- HCl = dipole-dipole and London dispersion force.
- Na2S2O3 = ion-dipole intermolecular force.
HCl + Na2S2O3 reaction enthalpy
- The reaction enthalpy of the HCl + Na2S2O3 reaction is -338.916 kJ/mol.
- Enthalpy of HCl is = −92.3 kJ/mol
- Enthalpy of Na2S2O3 is = −586.2kJ/mol
- Enthalpy of NaCl is = -821.98 kJ/mol
- Enthalpy of H2O is = -241,826 kJ/mol
- Enthalpy of SO2 is = −296.81kJ/mol
- Enthalpy of S is = −395. 8kJ/mol
- Reaction enthalpy (∆H) of HCl + Na2S2O3 = Enthalpy of product – enthalpy of reactant
- (∆H) of HCl + Na2S2O3 = -1017.416 kJ/mol – (-678.5) kJ/mol
- (∆H) of HCl + Na2S2O3 = -338.916 kJ/mol
Is HCl + Na2S2O3 a buffer solution?
HCl + Na2S2O3 is not a buffer solution, because the buffer solution is only formed between weak acid and weak base. HCl is a strong acid and Na2S2O3 is a salt.
Is HCl + Na2S2O3 a complete reaction?
HCl + Na2S2O3 is not a complete reaction as it is not a reversible reaction and cannot achieve equilibrium.
Is HCl + Na2S2O3 an exothermic or endothermic reaction?
HCl + Na2S2O3 is an exothermic reaction because it has the negative value of enthalpy of formation. The HCl shows exothermic and Na2S2O3 shows endothermic reaction as it is a salt.
Is HCl + Na2S2O3 a redox reaction?
HCl + Na2S2O3 is a redox reaction because the oxidation number of sulfur gets changed in the reactant and product. The oxidation number of the S atom in Na2S2O3 is +2, in SO2 is +4, and in sulfur, metal is zero. This is a form of disproportionate reaction.
Is HCl + Na2S2O3 a precipitation reaction?
HCl + Na2S2O3 is a precipitation reaction because the sulfur metal gets precipitated as a product in the reaction.
Is HCl + Na2S2O3 reversible or irreversible reaction?
The HCl + Na2S2O3 is an irreversible reaction because in this reaction the product cannot give back the reactants.
Is HCl + Na2S2O3 displacement reaction?
HCl + Na2S2O3 is a double displacement reaction and not a single displacement reaction. In this reaction, the atoms get exchanged and none of the atoms get displaced with other higher reactive atoms.
How to balance Na2S2O3 + KMnO4 + HCl = Na2SO4 + MnCl2 + KCl + H2O?
The steps to the balanced chemical equation of the Na2S2O3 + KMnO4 + HCl reaction are given below.
- Add 5 on LHS and RHS to make the balanced Na atoms we get.
- 5Na2S2O3 + KMnO4 + HCl → 5Na2SO4 + MnCl2 + KCl + H2O
- Then add 2 on LHS and RHS to balance the K, Mn, and Cl atoms we get.
- 5Na2S2O3 + 2KMnO4 + HCl → 5Na2SO4 + 2MnCl2 + 2KCl + H2O
- Finally, add 6 before HCl and 3 before H2O to balance all atoms of the equation we get.
- 5Na2SO3 + 2KMnO4 + 6HCl → 5Na2SO4 + 2MnCl2 + 2KCl + 3H2O
How to balance K2Cr2O7 + Na2S2O3 + HCl = KCl + Na2SO4 + CrCl3 + H2O?
The balanced chemical equation of the K2Cr2O7 + Na2S2O3 + HCl reaction is given below.
- Add 3 on LHS and RHS to balance the Na atoms on both sides we get.
- K2Cr2O7 + 3Na2S2O3 + HCl → KCl + 3Na2SO4 + CrCl3 + H2O
- Then add 2 on RHS before KCl and CrCl3 and 8 on LHS before HCl we get.
- K2Cr2O7 + 3Na2S2O3 + 8HCl → 2KCl + 3Na2SO4 + 2CrCl3 + H2O
- Finally, add 4 before H2O to balance the whole equation we get.
- K2Cr2O7 + 3Na2SO3 + 8HCl → 2KCl + 3Na2SO4 + 2CrCl3 + 4H2O
Conclusion:
The HCl + Na2S2O3 reaction forms the products NaCl, H2O, SO2, and S metal. It is a double-displacement, redox, and precipitation reaction. It shows an irreversible exothermic reaction. It cannot form a buffer solution and has a reaction enthalpy value of -338.916 kJ/mol.
Read more facts on HCl:
Hello everyone, I am Dr. Shruti M Ramteke, I did my Ph.D. in chemistry. I am passionate about writing and like to share my knowledge with others . Feel free to contact me on linkedin