Sulphuric acid (H_{2}SO_{4}) is one of the important mineral acids, and MgO is an oxide. Let us understand the various aspects of the reaction between H_{2}SO_{4} and MgO.

**Sulphuric acid is also known as oil of vitriol as it is prepared from green vitriol. Magnesium oxide is a white powder-like substance. During this reaction, the temperature of the reaction mixture rises.**

As the article flows down, all the essential features of the reaction between H_{2}SO_{4} and MgO will come to light.

**What is the product of H**_{2}SO_{4} and MgO

_{2}SO

_{4}and MgO

**Magnesium sulfate (MgSO _{4}) and water (H_{2}O) are the products of the reaction H_{2}SO_{4}+ MgO. **

**H _{2}SO_{4} (aq) + MgO (s) = MgSO_{4} (aq) + H_{2}O (l)**

**What type of reaction is H**_{2}SO_{4} and MgO

_{2}SO

_{4}and MgO

**H _{2}SO_{4} + MgO**

**falls under the category of neutralization reaction as the reaction produces sulfate salt and water by reaction between an acid and base.**

**How to balance H**_{2}SO_{4} and MgO

_{2}SO

_{4}and MgO

**The equation for the reaction H_{2}SO_{4} + MgO**

**is**

**H _{2}SO_{4} + MgO = MgSO_{4} + H_{2}O**

**The reaction is already balanced as the number of atoms of all the four elements H, S, O, and Mg are the same on both sides.**

**H**_{2}SO_{4} and MgO titration

_{2}SO

_{4}and MgO titration

**MgO being insoluble salt, is back titrated by H_{2}SO_{4} to determine its amount using the following procedure.**

### Apparatus

**Pipette, measuring cylinder, volumetric flask, conical flask, titration stand, and burette**

### Indicator

**Phenolphthalein is used as indicator in this titration.**

### Procedure

**Dissolve MgO in an excess amount of standard solution of H**_{2}SO_{4}in a conical flask.**After mixing it properly, add 1-2 drops of indicator.****Titrate the excess amount of H**_{2}SO_{4 }after reaction with MgO with standard NaOH solution from a burette till the color changes to light pink.**Repeat the procedure 2-3 times and take the average burette reading.****Finally, using the formula S1V1 = S2V2, the amount of unreacted H**_{2}SO_{4}can be found.**The amount of H**_{2}SO_{4}reacted with MgO can be obtained by subtracting the amount of unreacted H_{2}SO_{4}from the total amount of it.**From the amount of H**_{2}SO_{4}reacted with MgO, the amount of MgO can be determined.

**H**_{2}SO_{4} and MgO net ionic equation

_{2}SO

_{4}and MgO net ionic equation

**The net ionic equation for H _{2}SO_{4} + MgO**

**is**

**2H**^{+}(aq) + MgO (s) = Mg^{2+}(aq) + H_{2}O(l)

**The following steps are followed to get the net ionic equation.**

**Write dissociated cations and anions only for soluble ionic compounds.****H**_{2}SO_{4}and MgSO_{4}being ionic, dissociate into cations and anions.**The complete ionic equation is****2H**^{+}(aq) + SO_{4}^{2-}(aq) + MgO (s) = Mg^{2+}(aq) + SO_{4}^{2-}(aq) + H_{2}O (l)**Only SO**_{4}^{2-}ion is the spectator ion**here, the****cancellation of which will result in the net ionic equation.**

**H**_{2}SO_{4} and MgO conjugate pairs

_{2}SO

_{4}and MgO conjugate pairs

**Sulfate ion (SO**_{4}^{2-}) is the conjugate base of the molecule H_{2}SO_{4}.**MgO does not have a conjugate pair because it is a metal oxide.**

**H**_{2}SO_{4} and MgO intermolecular forces

_{2}SO

_{4}and MgO intermolecular forces

**Dipole-dipole and H-bonding these two**are present in H**intermolecular forces**_{2}SO_{4}molecule where H-bonding is more significant.**Electrostatic force of attraction****is present in MgO as it is ionic in nature.**

**H**_{2}SO_{4} and MgO reaction enthalpy

_{2}SO

_{4}and MgO reaction enthalpy

**For H _{2}SO_{4} + MgO**,

**the reaction enthalpy value is -145.4 kJ/mole.**

Compounds | Enthalpy of formation (kJ/mole) |
---|---|

H_{2}SO_{4} (aq) | -909.3 |

MgO (s) | -601.7 |

MgSO_{4} (aq) | -1370.6 |

H_{2}O(l) | -285.8 |

**Table representing enthalpy of formation values of all compounds**

**Reaction Enthalpy = Enthalpies of formation of [MgSO**_{4}(aq)+ H_{2}O(l)] – Enthalpies of formation of [H_{2}SO_{4}(aq) + MgO (s)]**= [(-1370.6) + (-285.8)] – [(-909.3) + (-601.7)] = -145.4 KJ/mol.**

**Is H**_{2}SO_{4} and MgO a buffer solution

_{2}SO

_{4}and MgO a buffer solution

**H _{2}SO_{4} + MgO**

**cannot be a buffer solution as**

**H**

_{2}SO_{4}is not a weak acid.**Is H**_{2}SO_{4} and MgO a complete reaction

_{2}SO

_{4}and MgO a complete reaction

**H _{2}SO_{4} + MgO**

**is a complete reaction because it is a neutralization reaction.**

**Is H**_{2}SO_{4} and MgO an exothermic or endothermic reaction

_{2}SO

_{4}and MgO an exothermic or endothermic reaction

**H _{2}SO_{4} + MgO**

**is exothermic in nature as -145.4 kJ/mole heat is released.**

**Is H**_{2}SO_{4} and MgOa redox reaction

_{2}SO

_{4}and MgOa redox reaction

**H _{2}SO_{4} + MgO**

**is not a redox reaction as oxidation states of the atoms H, S, O, and Mg are intact before and after the reaction.**

**Is H**_{2}SO_{4} and MgO a precipitation reaction

_{2}SO

_{4}and MgO a precipitation reaction

**H _{2}SO_{4} + MgO**

**is not a precipitation reaction as the product MgSO**

_{4 }is a water-soluble solid, and the other product is water.**Is H**_{2}SO_{4} and MgO reversible or irreversible reaction

_{2}SO

_{4}and MgO reversible or irreversible reaction

**H _{2}SO_{4} + MgO**

**is an irreversible reaction as it is a neutralization reaction.**

**Is H**_{2}SO_{4} and MgO displacement reaction

_{2}SO

_{4}and MgO displacement reaction

**H _{2}SO_{4} + MgO**

**is a displacement reaction as SO**

_{4}^{2-}and O^{2-}ions are swapped between two reactant molecules, H_{2}SO_{4}and MgO.#### Conclusion

In conclusion, when sulphuric acid reacts with magnesium oxide, the products are metal sulfate salt and water. MgSO_{4} is a water-soluble white solid used as a medication for different health issues.

Hello, I am Tuluma Das, Completed my Ph.D. in Organic Chemistry from the Indian Association for the Cultivation of Science. I have a total of 9 years of research experience including a Ph.D. and Postdoc and 3 years of teaching experience. I have published 7 papers so far in international journals. Let’s connect through Linkedin :